Upgrading from 60D or buy a good glass? Tight budget

[AutumnApple]

I am sorry if this question pop up a lot but I'd be appreciate some recommendation for my case.

I have been using Canon 60D for a while, mostly for my kid's pictures and occasionally landscape or wild animals. 

I got 3 STM lens to cover what i need: 18-55mm, 50mm, 55-250mm. (going to be given 70-300 IS USM II). Problem is running outside with a kid, there's hardly a chance for switching lenses, I found myself using 55-250 most of the time, to get some decent photos of my kid and some room for nature photos but that also mean lots of struggle when wide angle is needed.

Now I'm thinking of 2 options:

- sell my lenses and get Canon 24-105mm L lens for all purposed.

For this, would I gain higher image quality ? Would this still produce good boker since it's f4. I am ok with shorter zoom. 

- or should I upgrade my 60D to 6D and keep 50mm STM with 70-300 IS USM II? 

Would this option yield better result in general compared with lens upgrade?

I had pretty bad luck with third party lenses so I'd prefer to avoid them at all cost. Thanks for reading and I'd much appreciate to hear some recommendation.

[ebiggs1]

"I decided to keep my 60d for the moment, ..."

OK, fine so now let's concentrate in making it the best it can be.  It is no slouch either.  A very fine camera.  This does change my suggestions on what lens to buy.  Like Scotty suggested above, now me to, the Canon EF-S 17-55mm f/2.8 IS USM Lens is perfect.

It is better in all respects for a cropper like your 60D.  That fast f2.8 constant aperture is worth it.

"...i would be able to jump for full-frame."

When you do decide to go FF make sure it is for a valid reason.  Not just hype which abounds on the forums.  Most of it false or myths.  Personally I would very much prefer the 7D or better yet the 7D Mk II over the 6D any day.