i think the prices that they cammand are just cause they are so rare, even more so a complete set up, as for power gains sure they can make ya more power totally not dvkk power but youll be able to pull away (slowly) from your other 36er pals i think the 36 kit gives ya 40 or 50 hp im not 100% sure on that but it helps, as for the tranny i dont see a need to have anything beefier the kit was made in the era of the 36 and perf parts for a split case are slim im sure.
check out wolfsberg west i saw the other day they sell a brand new okrasa kit complete, i dont know of how they are but for the most part ww dont sell crap