If your roller body/chassis unit from N&N is going to a shop in Missouri to be finished out into a driver, they'll have the engine & tranny there too, right? Wouldn't it be easier to have them responsible for the driveshaft? Or maybe you're looking for suggestions on the suppliers so you can ask better questions of the shop regarding whose driveshsafts they plan to use so you're confident it can handle the power? A bigger question to me would be what rear gears are they going to get for the rear end, assuming you went with N&N's standard 9" Ford. It comes with housing & axles, but no pumpkin.