You need to provide more information...are you I4 or V6? Do you want auto or manual shift? Something as complex as swapping a drivetrain is almost never plug and play. Many different kinds of swaps have been done for these cars, if you're serious about it spend some time searching here and v6performance. Lots of info out there.
I'm v6 now. I'd like to keep the car v6 but since my gf will be driving the car daily I'd like to stay auto also. The problem that I'm ready on the forums is that v6 auto transmissions are no good. Is there truth behind this? Or is just a certain year frame that they are bad?
Unfortunately Honda's autos were unreliable up to and including 2003. I personally would only use a 2005+. Not all autos failed, but you never knew if you got a "good" one.