I have a friend that owns a screen printing company but he's in a different state than I. I can maybe try to get a hold of him and get some quotes. I don't think he does embroidery though. He can get different types of Tshirts, from cheap ones to Hanes Beefy Ts, with or without pocket etc.
On a newsgroup that I used to frequent (alt.coffee), before I got too busy doing real work, a fellow made up some shirts for the NG and sold them through amazon.com auction so the payment and ordering part was really easy to handle, sales price was a flat rate of course, not a true auction. Just an idea to handle orders and sales.
If there is enough interest for just screen printed Tshirts, I can get a hold of my friend...

Dave Clark
Austin, Texas
12g Blue MK2
S/N 80000329