now the posts above did not mention the single greatest difference between the two. the 7D is crop sensor and the 5DMkII is a full frame. now ask yourself if you need a full frame or a crop sensor is enough for your needs. i don't know what you need it for so i can't recommend anything to you.
Right now I'm a cinematographer for many short films in the highschool film world, but I want a DSLR for my freelance stuff, such as snowboarding, wakeboarding and skateboarding. I also know about the 5D's full frame and it does not sound too appealing, and glass jumps by about $200