The 30D can handle enlargements and posters with the right software. Heck, a pro 4MP DSLR can do enlargments with the right software and shooting in RAW.

The XTi is not bulky but maybe with the battery grip, you might like it. I just can't recommend the 30D since the XTi has the technology that 30D users want...10MP and sensor clean.

If you need 5fps and like spot metering then the 30D has it.

We are all speculating a 30D replacement in the Fall so maybe you can wait otherwise give the XTi a look and consider the battery grip for function and feel.

I don't know Nikons but I tried my friends D80 and it was nice.

Let us know what you decide.