Stop. Take a deep breath. Don't buy anything until you understand what you need and why you need it.
+1
In fact, the 7D requires more setup as you have the autofocus system to understand too
+2 the 7d AF is ridiculously unnessecarily complex, the AF on a 1d is simple and just does the job, the 7d is too much imo, you have to surrender too much control to the camera
The 50D is a fantastic body and at a fraction of the price of the 5D & 7D.
+3, although for high iso work i'd still consider the 5d classic over a crop cam, 5d mk2 is only marginally better than the 5d (like half a stop difference), where as I think there was considerably improvements to the crop cameras- although i'm a recent canon convert so i've never shot the 50d
Sorry but with all respect you don't have the knowledge needed to shoot weddings in any capacity other than as an uncle bob, or aunty whoever.
Whilst I respect you're asking questions to better your knowledge do you not think that as a wedding photographer you should know every aspect of your equipment as if it was an extension of your own arm?
+1
although my biggest failing is that I don't have the bottle to dive in and get started on something as demanding as wedding work, i'm technically able, and I have the gear- but I think i'll just stick to my studio work for now...
so credit to you
i'd also like to point out that 2.8 might not be fast enough for you, especially at the long end. IS isn't going to help you combat subject motion
i'd be much happier with:
5d with 24-70
5d with 135mm f2, 85mm 1.8 and 35mm 1.4
or maybe the 100mm f2, 50mm 1.4
basically what i'm saying is that you're going to need some low light capability at the tele range, and the short tele
I can't see myself shooting 2.8 at 200mm, i'd have to be shooting f2, or i'd want to get in closer with an 85/50 (50 might be too close)