whatever you do, i highly recommend rebuilding before installing. hindsights 20-20, and i can clearly see now that i should have rebuilt my CA (and my GTiR turbo) before i installed them. 5000km on the odometer, and the motor's making noise and the turbo is consuming oil, so it has to come back out and be refreshed

I like the CA though. My only gripe w/ it is how slow it revs. if i had the money for a lightweight flywheel and could source out an underdrive pulley, i'd be content.
RHD is a waste of time and a waste of money, but i can't help but want to do it all over again when i get tired of my S13 and move on to something else (read s14). If you're going to pay someone to do it, then theres no way its worth it and you'd be much happier spending the money on other modifications. If you're going to spend little and do it yourself, then there's a shot it'll be worth it.