Wow, that's quite a lot to get through.
I applaud you for investing in your glass first, but it's definitely time to give the body some attention. I don't mean to bad-mouth the Rebel series. My original Rebel 300D was downright respectable for a long time. But of the various components to photography, you will benefit most from a new body.
Given your shooting interests, I think a full frame will suit you best. Wide angle, available light.. these scream FF, but the downside, if you can call it that, is that it will open up new lens "needs".
24mm/1.4L, 35mm/1.4L, 24-70mm/2.8L II, the list of lenses that would help you goes on...
The 7D is a fantastic camera, but unless you're specifically shooting wildlife or sports (or something else where you would benefit from extra reach with your long lenses) the benefits of a FF sensor outweigh the 7D's strengths.
You can call the 5D2's autofocus crappy, but it's worked for many photographers. You simply become good at focus-and-recompose, since you only use the center focus point. It's going to take me some time to get used to trusting the 5D3's other focus points.
It really comes down to budget. Honestly, I would either go used 5D2 (in top condition) or new 5D3. Either would serve you well.