Shannon,
I've checked into those driveshafts but the rumor is Moss purchased a surplus of them from a manufacturer and when they are gone, they are gone. They have no idea about the serviceability of the cv joints nor do they have any real-world high hp application data. A lot of money for something not really proven yet. I'm still leaning the direction of the Corvair/Aluminum hub conversion.
The BMW electronics are a snap. You have to stay with an engine with OBD1 software/accessories as BMW ramped up their EWS in 1996 to make it virtually impossible to use their engines outside of their cars. Granted, some of these OBDII engines can be converted back to OBD1 but it takes a substantial investment. BMW made the S50 engine for the 1995 only M3. This was not the powerhouse available in Europe, rather a stroked 325 engine that could put out 240hp. Now, strip the cats and play with the chip, you can net a lot more without substantially degrading the reliability. BMW uses one box / harness / computer that has all necessary outputs including a wire for the fuel pump. The most difficult part is dealing with the 6 individual coils to get a good signal to a tachometer. Autometer makes an adaptor for this but you have to hook it into the main power lead to the coils before they split off. The speedo is a problem as well and I will be taking an impulse signal from the Q45 diff ABS sensor to calibrate to it. All other engine data is electric as well so conversion or replacement of the instruments is mandatory.
I'm still at the point of crossing my fingers but the reality is setting in that this dang Frankenstein is actually going to work.
Dave