At the balls in Scotland I've been to- generally white tie type evenings, there have always been a few horsehair (or other long hair) sporrans about - generally antique ones, with nicely made sterling silver cantles. At a guess, I'd say that they'de been inherited. Looks best with some form of velvet doublet/jacket - a combination which to my eyes looks pretty good. Wouldn't wear one of the generally available piper's sporrans, though.

Oh, and nobody ever wears white hose! :-)