SkaleTracker (http://skale.org) now has in it's SKM Format to OGG compress individual samples! Pretty useful! They have a Winamp Plugin and if I had to take a wild guess, i'm sure that plugin could be adapted to Modplug Tracker and Player to be able to play / save SKM Format (compressed and regular).
So heres yet another module format to toss into the mix, if at all possible.
-Dave