I'm assuming that no one's worked with this guy before:
http://cgi.ebay.com/ebaymotors/Pontiac-Custom-Adapters-Spacer-Custom-Built-Rim_W0QQcmdZViewItemQQcategoryZ42614QQihZ012QQitemZ220183699887QQrdZ1QQsspagenameZWDVWThis is the kind of shop that you have to get your adapters from if you want to put Gen 2 wheels on a Gen 1 W-Body. Tempting to say the least.
I'm still sitting with an extra set of Gen 2 wheels for the GP, but I also saw a wicked set of 17" chromes that would go great with those adapters on the '95 Coupe. It's winter, the car's about 5 months from being insured again, but the gears in the head are already turning!