My understanding of driveshaft making is that you need to get u-joints at both ends (unless your 205 is a slip yoke, then I have NO clue) and measure from the center of each cap. The driveline shop then figures all the rest out.
It is MUCH cheaper to go to the driveline shop with pieces they can use, at least half price around here. Need yoke(s) and the slip section if not a slip yoke t-case.
As to material, there is nothing inherently wrong with AL or carbon fiber shafts, both have been used in stock and non-stock applications with no problem. However, I would be pretty leery of the aluminum if I had ANY potential of hitting it with anything like a rock or tree. Thin steel probably isn't much better for impact, it doesn't take much to weaken a shaft, but it would still be better than aluminum. As a for instance, I don't believe any of the light duty trucks (at least) ever used an aluminum shaft, but I've seen carbon fiber. Probably extremely expensive to have either made, compared to steel.
