Can you guide me which digital camera best for my profession?

Hey guys, this is my fist time in this forum, and I am really exited. I'm a beginner photographer and I'm thinking in buying my first canon camera. Most of what I do is portrait, Wedding and fashion photography and I'm still confused which canon camera should i buy. My options are EOS 40D, EOS 450D. Please let me know which one do you think is the best camera for me? My friend refer me one site provides for digital camera reviews. Also, what kind of lenses you recommend would be better to get for this camera?

How about getting the Ikelite housing:

http://www.ikelite.com/web_two/can_450d.html

Get a Canon 10-22 lens.

Alex