Maybe you will like these better. I try to please! 
All with my best of class, 1.3 body the EOS 1D Mk IV. Birders favorite camera! I love this camera.
Bob from Boston has, again, hit the ball squarely out of the park with this reply ...
"Ernie's talking about his 1Ds Mark 3. It's a large, heavy, very expensive ($8000 price added) full-frame camera from several years ago. It has since been replaced by the 1DX, another large, heavy, very expensive full-frame camera. Both are designed for long life and abusive use under challenging conditions. Unless that happens to be what you need, you should probably not consider buying one. In your particular case, you'd have to be crazy."
You would have to be crazy. It is a rather well known fact, I am crazy. In you case the ultimate camera is the 5D Mk III. As a matter of fact if I could have just one body, the 5D Mk III would be my number two choice. The 1D Mk IV being my number one. There is no camera made like it.
Now to help clarify a few other points that have gotten skewed and twisted.
First and formost you need to commit to menory the 'normal' f-stops. I am going to repeat them here. You memorize them!
f1 - f1.4 - f2 - f2.8 - f4 - f5.6 - f8 - f11 - f16 - f22 - f32 - f45
If this proves too much, you really have to simply remember two numbers. OK? Remember 1 and 1.4. All f-stops require the use of one of these numbers.
The reason I say you need to know this is because you seem to think a f2.8 will make a big difference in, say, night time photography. But in reality it is just one stop. Is one stop going to make or break a situation? Yeah, sometimes it will. But for the most part of the time it will not.
Now you say where is my f1.8 50mm? Easy. It is not a full stop. There are besides the full numbers I listed above but there are also half and one-third stops. f1.8 falls into the 1/3rd range. To me, IMHO, there is no good reason to make a f1.8 lens. It is in practical use a f2.
The f2.8 lenses, specificaly the 24-70mm f2.8 and the 70-200mm f2.8 are just better lenses all around and in every spec not just the fact they offer a better f2.8 over the more common and cheaper f4 versions. It is just one more feature of the better lens. However in the end, in your hands, out in the world, it is just one stop faster. Capisce?
Now back to the nifty-fifty subject. On a FF camera the 50mm focal length gives an approx view that is common to most human eyes. That is why it is called a normal lens. It is not a bad portrait lens but not a good one either. For that job a 85mm is much better. Why? Because it tends to flatten the face slightly. IE, makes girls noses look smaller on their face. That sorta thingy amoung others.
However, on your cropper the 35mm becomes the lens that provides the normal view ( the human eye thingy). So it is called the normal lens for it. The 50mm now DOES become the lens of choice for portraits for the same reasons as above.
You have a pretty nice lens inventory started with what you have already. The addition of a 50mm f1.4 and a 35mm f1.4 or f2 would be a logical choice. But you do know that either of the lenses you have already cover that focal length? You will buy the 50mm and/or35mm and/or both for more than just their focal length. Right? Of course, right!
I want better IQ and a faster lens. Fine that makes sense, got fo it. If that is your reasoning, I am all in for you. I just want that focal length is not a good reason.
Now, yes there is a newer EF 50mm f1.2 L II. There was a first version, too. The second version is even better than the first. This is the ultimate 50mm, in my book. It is wonderful and needs to be used on a FF camera like the 1Ds Mk III.
It is a hard lens to use and not recommed for rookies a s a first 50mm. It is slow to focus along with its big brother the EF 85mm f1.2 L. These lenses have extremely shallow DOF for one thing. Sometimes in the fractions of an inch!
As I say they both are wonderfully fantastic, I just love both. They a both very expensive.
Did that cover everything?
"Biggs likes stuff that will take a licking and keep on ticking."
You are right here, too. But when I retired I had to decide on what to keep and what to get rid of. I prefer the larger size of the 1 series cameras so all the other, of which there were many, got the ax. So to speak , as I sold most. But I gave most of the Rebels to family members.
Now in retirement I buy lenses and sell the lenses I don't like. There have been many there, too. I lose money on each one but the time playing around testing and using them is worth something. Isn't it? I am having a ball, more fun in photography then I ever did before. It has been born again for me. Probably because I don't have to. I do take a job now and then but I don't actively seek any.
I only buy certain lenses. Ones I deem worthy. I steer clear of the junk as I have no interest. This philosophy makes them very easy to sell especially when they include all factory packaging, parts and papers, at a very attractive reduced price. I had one sell in 10 seconds one time. I literally, barely, got my finger off the <enter> key.
I now have built up a consensus of what is a good lens and what isn't. Expensive? Yes but a great trip to be on. Plus I don't care what the rest of the folks think. I know what I know.
But maybe I am crazy and all this is just a dream. Pinch me! 
Did that cover everything? 
Obiwan I really, really, got to give you your game here (thumbs up) Not only for your knowledge but also as my teacher. I agree with the crazy at times .....BUT, Crazy or not, you do know your stuff.
You cleared up all my questions....for once 
You clarified a couple questions I did'nt even ask about, I've had in the back of my head for awhile. Far as the 50mm range you're right about my thinking here. Yes, I knew my present lens also covers 35mm/50mm. As you said I want a prime for better IQ and faster aperture speed. Had'nt thought till now to get both, I only thought about 50mm. From what you say here I will get both, again I trust your judgement. And thanks for the info on the L's. I surely will not get L's in either lens. I do want good ones though, no cheapies.''
Far as the F stops I was'nt aware that's what you were referring to in your privious post. I got the F stops Obiwan. Other than the 35/50mm, the only other lens I have on my list is something in the 600mm range. A zoom, not a prime. I will need one for shots like your bird and horse shots. Then I will be satisfied my lens collection is sufficent, though I may add more as my needs dictate. I do want to make sure I don't unnessrarily duplicate any of my lens.
This is very good info, and for me...... a great photography lesson
