Ok, so you're probably all hating on me since there are a lot of threads like this - but I can't seem to find one where someone is in the same boat as me!! so if you have some time and have some suggestions for me i'd appreciate it! 
Last winter i had a job doing shots for a band (not a well known band, just a local one) so all their gigs were in very awful lit bars. I have an XTi currently and had a hard time with trying to shoot with just 2 small spotlights in the whole room. i really don't like using flash but sometimes just don't have a choice. i'm still learning when it comes to photography - i've had my XTi for a little bit now but i'm by no means an expert! But the manager of this band told me she had some other bands who were looking for photos too, so i'm assuming that this winter I will be doing a lot more of this!
Lately, I find myself using my camera in non-well lit places more than in well lit places, and my XTi just isn't cutting it anymore! ISO 1600 IMO isn't that usable. I do all kinds of photography tho - sports, landscape, wildlife, concerts - so this is where my confusion comes in. I was fully set on the 5d Mark II, but now i see the 7D is out and is $1000 cheaper. I am realllly picky when it comes to image quality tho - i will say that. The 7D i've seen some amazing shots with, and of course some shots that def. didn't make me want to buy it, but it all depends on the photographer so I won't judge too much yet! But shooting wildlife and sports i'm not sure i want to go from a crop to a full frame. The longest lens i have so far is the 70-200. But i've also heard the 7D is a lot better for shooting moving objects. I like to take pics at my sister's basketball games and my dad raises birds so i also like to get shots of them.
Should I go full frame and just keep my XTi for the crop (even tho it's not really usable in low-light)? or should i get the 7D and sell my XTi? If the 7D does really well in low-light then i think it's safe to say i'd go for that until i actually figure out what my specialty will be and then go from there, because i'm sure that would be a lot better than what I have now! I would like to do concert photography but as of right now i'm doing a little of everything. I also would like to get into doing some senior portraits and stuff like that for extra money, so the 5D Mark II would probably be nicer for that, but if i can save $1000 to put towards another lens then that would def. help! I just don't want to get the 7D and be disappointed and wish i had just gotten the 5D Mark II tho. That right there is my biggest issue since i'm so picky!
Does anyone have BOTH the 5D Mark II and a 7D that could offer me some advice? I def. can't afford to buy both. Or maybe post some shots comparing both under the same circumstances that would help me decide? (or even point me to where there are some?) Thanks in advance! 

