The 6-speed drops right in, but you'll need a new TT flywheel, TO bearing, pilot bearing ,wave washers, slave hydraulic line, tranny cross member, tranny mount, and all the 6-speed components in the bell housing (release fork, TO bearing hub, slave cylinder, etc).
Then, you have to decide on a clutch setup. You can get anything from a stock pp/clutch disk to a carbon-carbon triple disk Tilton. Just depends on your application and torque requirements.
Finally, you should consider a 6-speed pumpkin to go along with the getrag tranny. I've run both the auto TT and 6-speed LSDs with my getrag, but the gearing is too short with the auto LSD, IMO. Consequently, I have a full Supra 6-speed driveline and love it.
BTW, be prepared to spend $5k minimum on the conversion for parts only. That's what it cost me, and I did the install myself.