I've had a Rebel for about a year and a half, and have shot a lot of pics, did some portraits, and learning more about pro photography. I'm in no way a professional. However a couple in their late 60's at church is getting married and they asked me to be their photographer. I tried to say no, but they insisted. So in the last 4 months (since they asked) I have been doing a lot of research and practice. I have a Rebel w. a Speedlight 270EX, and 3 lenses (18-55 EF, 55-250 EF, and 50MM). A retired photographer friend of mine, is a Nikon guy and gave me a D200 w/ a 28-200 lens & a speedlight SB-800 flash. His camera, from what I can see and research is a notch above my Rebel, plus his flash seems equivalent to the Canon 540 or 580 EX.
My question is which camera should I use for this wedding? Should I shoot w/ both? Thanks in advance.