there is another vid of it driving:

http://www.youtube.com/watch?v=tiX8A9fexDU&feature=related

Just take the countershaft sprocket, machine the teeth off it and then use it as a flange to mount your driveshaft to.
Reverse, you can either use an electric drive or something like a quaife reversing gearbox. There is a guy on PF that actually uses the original gearbox from his starlet mid mounted. Leaves it in 4th when going forward using the busa box and then changes it into reverse when necessary. Just imagine all six speeds in reverse