All the currently offered Canon DSLRs would meet your still photography needs for the large part. Some are better at sports/action (higher frame rates, faster/higher performance autofocus) while others are better at low light (full frame models) or for really large printing (also full frame, but especially the new 50MP full frame 5DS models coming soon).
I don't do videography with my DSLRs, so really can't advise very much about that. The latest 70D, T5i and T6i seem to be pretty full featured for that purpose.... and STM focus drive lenses often seem preferable (quieter and smoother focusing) for video. But, hey, I really don't know much about it so I'll leave it for someone else to recommend any more about video.
Lenses might be more important than the camera itself. In fact, one of the key reasons to buy a DSLR is the ability to change lenses and adapt the camera to a wide variety of different situations. Canon offers a huge selection ranging from entry level, to moderately upgraded and on up to premium quality lenses.
Basically, when it comes to lenses the more entry-level type tend to mostly use micro motor focus drive. For about $50 more per lens, some models are offered with STM (stepper motor) focus drive instead, which is faster, quieter and smoother operating, as I mentioned above. Even farther upscale and generally more expensive are USM (ultrasonic/ring) focus drive lenses, which are the fastest and best tracking moveming subjects, as well as quiet (although not as quiet and smooth as STM).
In the Canon lens line-up you'll find EF-S and EF lenses. EF-S are "crop only" and EF are "full frame compatible. Canon's APS-C size sensor cameras (pretty much everything other than 6D, 5D-series, and 1D-series models) can be used with either type of lens. Canon full frame sensor cameras (6D, 5D-series, 1Ds-series, 1DX) and APS-H size sensor cameras (1D-series) can only be used with EF lenses... EF-S lenses are designed so that they cannot even be physically mounted on these cameras.
Another thing you'll find in Canon lenses is IS or Image Stabilization. This is an important technology that can be helpful getting steadier shots at slower shutter speeds. Not all lenses have it.... I've been using some with it for as much as 15 years now and love it on telephotos especially, which are harder to hold steady. It's nice to have on any lens, of course, but I especially look for IS on 70mm and longer lenses.
Various camera models are offered "in kit" with certain lenses. This is often a great way to buy, you get a nice discount compared to buyihng separately. Exactly which lenses are offered varies, but usually it's at least an EF-S 18-55mm IS (either in the micro motor or STM version). Some cameras are offered with a bit more versatile EF-S 18-135mm IS (also either in micro motor or STM focus drive versions). Or, sometimes two-lens kits are offered with EF-S 18-55mm IS and EF-S 55-250mm IS (also avail. in micro motor or STM). Sometimes a cheaper EF 75-300mm is offered instead of the 55-250mm, but I'd recommend the 55-250mm instead. It's a better lens optically and in other ways.
All the above EF-S lenses are usable on the APS-C camera models such as SL1, T6i, T5, 70D, 7D Mark II.
If you were to buy a full frame camera instead (say a 6D or 5D Mark III for example), in kit it would most likely be bundled with EF 24-105/4L IS USM or EF 24-70/4L IS USM lens.
Some retailers put together their own bundles or even work with you to assemble your own. Depending upon your budget, that might allow you to upgrade to other lenses not normally bundled with these cameras. For example, the EF-S 10-18mm IS STM, EF-S 10-22mm USM, EF-S 60/2.8 USM Macro, EF-S 15-85mm IS USM and EF-S 17-55/2.8 IS USM are all "crop only" lenses that might be wanted, instead of or in addition to what's normally offered in kits. For full frame there are even more EF lens possibilities, from wide to standard to telephoto, zooms and primes... as well as specialty lenses such as macro, tilt-shift, portrait, etc.
I suggest you try to think in terms of a system of gear, workign backwards from what you want to do with it and what will be necessary for those purposes. Map it all out and gather info about anything you're unsure of, then set your priorities. This should really help you decide what to get now, how far you can stretch your budget, what to plan on buying sometime in the future, etc. Things may change, of course, but having a plan should really help. Basically I recommend buying the least expensive camera that will do the things you need it to do, and leaving as much as possible for lenses and other necessary accessories (memory cards, flashes, tripods, filters, etc.)
If you want to make your budget stretch, shopping used is one way and KEH mentioned above is a good source. B&H and Adorama both also have large used gear deparments. (I just bought a Canon drop-in filter from B&H and a bunch of memory cards from Adorama.... they both have gotten a lot of my money over the years! So has KEH.) There's also the Canon Online Store at http://shop.usa.canon.com/shop/en/catalog They sell refurbished cameras and lenses there, nicely discounted too. Amazon... especially Direct... is also a good source. Mostly new stuff there, though I've picked up some used items from individual sellers there too. Your local Craigslist can be another good source of used stuff... but you have to know values, be careful and fully inspect anything bought through CL... Pretty much no warranties on stuff when you buy from individuals on CL or Amazon or, for that matter, eBay. The stores, OTOH, often offer at least a 60 day or 90 day warranty on used gear they sell.
I don't have Instagram and would suggest you set up on Flickr to showcase your work. You can put a lot up there for free, or upgrade to unlimited storae for about $25 a year I believe.
Wherever you put your stuff online, be careful. I watermark everything and only post smaller, lower resolution images. Plus I register the copyright of my more important stuff.... All because people think anything on the Internet is free for the taking. Also, if taking and especially if posting images of people online you might be wise to start learning about and using model releases... I sure wish I'd gotten in the habit of getting them earlier, starting when I first seriously got into photography.
Have fun shopping!
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Alan Myers
San Jose, Calif., USA
"Walk softly and carry a big lens."
GEAR: 5DII, 7D(x2), 50D(x3), some other cameras, various lenses & accessories
FLICKR & EXPOSUREMANAGER
