[Dr.Viggy]

do you have an inventory of items that you want to sell or do you want a merchant to create and sell them for you based on your design? if you chose the latter then just go to cafepress.com and set up your online store. each item is made to order and shipped directly to the customer. you can alter the prices and create markup so you can profit from the items as well.

plus there is a hack for vbulletin which will integrate your cafepress store with your forums.
www.cafepress.com/drviggy is mine so you can get an idea. or go to www.drviggy.com/forums and click on the "shop" link to see the integration.

here is the thread with the hack