How did most of you acquire your driveshaft? Did you get one from a donor car and have it cut to lenght? Did you get a completely new custom one?

I haven't found a local shop that does this kind of work (at least not professionally), and I was wondering the best way to go.

What the difference between a regula yoke and a slip yoke? Will a slip yoke account for any horizontal (forward and backward) movement as the the rear end moves up and down?