Howdy,
        As for the Sportomatic (60s & 70s made) it bolts right up to the
aircooled engines which, I think, means it doesn't bolt right up to the
watercooled engines.  The triptronic, again expensive, is similar
although I don't know specifics.  I'm pretty sure Kennedy makes adaptors
for them.  If I had the $$ I'd definitely do a triptronic, they will
handle all kinds of hps, are smooth and very versitile!  I had the
chance to drive one (a 911 with the triptronic) on the track and it was
amazingly usable in that context.  You could jam it into different gears
easily or just forget it and it would do the work pretty well.  I know
some of the transmission places listed in VW mags that do Buggies and
drag cars can tell you more about how these trannies match up.

Good luck,
Eric