OK folks, I took the plunge and bought a 250-count pack of glossy card stock today for $21.99. This is great stuff. I highly recommend it. Now that I have the package I know the brand name and can find it elsewhere. BUT, the pack is very heavy and so shipping would be a killer. Probably best to just get it at Kinko's. It's Mohawk brand Ultra Gloss cover 90 pound/218 gsm, stock number is 37-104. Here's more info:
Mohawk Card/Cover Stock Ultra Gloss Color Copy/Laser Paper, White, 90 Brightness, Letter, 250 Sheets (37-104) - SuppliesPlus.com