Well I must admit I am surprised too but I couldn't find anything either. Depending on how subtle you go (I assume there are copyright concerns), can you use a custom stool design place like this (first one I found, not recommending):
http://www.seatsandstools.com/logo-and-personalized-bar-stools-c-198.html?gclid=CM3ixejcsMICFciEfgodMSQA9g
For TSPP maybe go with just outline of Bart's head or something along those lines...