it really depends on your application.
if its going to be for a drag car, you may not want to go with the t-5.
im no expert by any means, this is just what ive gathered from reading these forums.
if its for a street car, it depends on your traffic patterns. if you have heavy traffic, an automatic would be nice.
if you ever want to go on the highway, a c4 isnt going to be so fun ( on your wallet )
with the t5 swap, you need the tranny of course, the pedal assembly, the clutch, quadrant, cables, and a WHOLE lot of other stuff, INCLUDING A 5SPEED COMPUTER. the aod eec in your car now will not work. also i believe the drive shaft needs swapped as well (length?)
ive been looking into swapping as well.
honestly, ive found my best bet is to stick with the aod.
ive looked into all my options, and it is the easiest, most appealing, and probably the cheapest in the end.
look into a performance AOD.
such as the art carr AOD extreme. or get a heavy duty race REBUILT aod, with a high stall torque converter, take it to a shop (or do it yourself) and have the TRANSGO shift kit installed. runs about 120 bucks from summit, increases 1st gear shift to 4900 rpm, and each other gear 1000rpm above stock, and lets you downshift at any rpm. i hear it gives you nice sturdy shifts that actually chirp a little bit.
all in all, a good aod setup might run you about 1500 - 1800 bucks. by no means cheap. but consider the labor costs, even if you do it yourself.
its all up to you man. if you think you can handle the swap, and really want the standard, then go for it. otherwise, the aod is workable.