I got a T7i as a travel camera and to compliment my full frame. I have been very pleased with it. I may step up to the replacement to the 7D mark II (whenever that is) but so far the T7i has worked out well so maybe I will apply that to lens instead.
I have never used an SL1 so I do not know the differences between the two but as someone else said, sit down and read the manual (or better yet one of the thrid party books). Then, if you really want to get the most out of it, get the best glass you can afford. If L series glass is out of your range consider the EF 70-300mm f4-5.6. I have some L glass but this lens was unexpectedly good in comparison and at $500 a real value - that is if you need this type of lens for what you shoot.