Um. We made a buncha products based on the most likely looking combinations, the items available to us from Cafepress, and all the logos Bons could make while she was neglecting things like the rest of her life. If anyone has a specific suggestion that Cafepress offers, we'll add it. Some new products are coming soon... including a very limited-edition-don't-blink-or-you'll-miss-it boxer design.
A classic combo with either boxers or thongs would be the spaghetti strap tank or a ribbed tank. In, of course, unisex sizing.
Outside of actually placing an order, and the free baby t-shirt, I was not being totally serious. Kudos to Bons and the rest of you for the selection offered. It is a fun idea and hopefully it will work out well.
In the future I might the suggest using some of the pithier comments of the modders and mods' characters for slogans. I realize you could not use Bioware quotes but I know there a thousands of funny/ witty quotes from in-mod, in-forum, in fanfiction and irc. Perhaps these quotes would be too insider but I think they could be quite popular and fun. Just a tee with <charname> or If ~ Then, etc. could be very funny.
Best of luck with whole endeavor.