A manufacturer called Iraggi out of Texas makes high power alternators, 180
to 240 amps, and they list several on eBay that are supposed to fit
Vanagons. It seems like higher power would provide a partial solution to the
unending problem of drawing too many amps with the accessories.

Anybody ever used these?

Here's a link, though they never seem to work right on eBay:
http://cgi.ebay.com/ebaymotors/200-amp-Iraggi-Alternator-86-93-Audi-Volkswagen_W0QQcmdZViewItemQQcategoryZ33573QQihZ018QQitemZ7957000497QQrdZ1