You already know that power level is hard to control you will need serious clutch, flywheel and the rest eg. brakes, suspension and rear end. You would seriously consider a steel bellhousing to suit either a tremec or t56 6 speed which are becoming popular recently with RB rwd only setups due to tremec parts prices and availability not to mention rb boxes getting older these days.
Save your legs and save money on anti-shatter blanket.
http://i789.photobucket.com/albums/yy ... CSTURBOCUSTOMS/tranny.jpg
gearlever positioning choices
http://faststreetcars.com/imgs/tr-6060-tailshaft-housing-swap.jpgbox lengths
http://faststreetcars.com/imgs/turbo-build/T56%20dimensions.jpgThis version is popular with the rotary guys making big numbers
there was a group buy a while back with steel bellhousing and
the beauty is you can just unbolt 4 nuts and box slides off.
http://forums.nicoclub.com/tremec-tranny-for-rb-t448047-90.html