My family has been in the professional photography business for over 30 years, I worked at the studio for about 10 years and video has always been a hobby of mine. We have had both cameras at our studio and I have tested both extensively. Our studio shoots 80% of their stuff on 5d's, the rest on 1ds's. The 5d is a very nice camera, that is going to get you the full frame sensor which is going to give you a better picture, especially in low light situations. I doubt you are going to have access/knowledge to properly light low light situations yet, so the 5d will help you in that regard. It also is going to give you better color right out of the camera which may help if you are not an expert color guy/finisher in the computer. It is easily the better camera.
All that being said, I would still recommend the 7d. It is going to get you close enough quality, it has more versatile shooting options as said before. And it is cheaper. Lenses are a huge part of the equation and I would put your money their. If canon lenses are killing your wallet, you could look at tamron lenses until you can afford to get all canons. they work great on canon cameras and are about 1/3 the price.
With this recommendation, I am making some assumptions about you. I assume your young, new to this, not an expert finisher, and have a limited budget. If you are a pro, or have aspirations of becoming pro very quickly, and your parents will buy you any body you want I would go 5d. But I would also keep in mind that canon should be coming out with a new 5d or whatever they are going to call it very soon.
They are both unbelievable cameras for the money, you really can't make the wrong choice. I would spend the money on lenses and computers and software if I was in your shoes.