Thanks, Deanpaul. I found a place called eRubberStamp that quoted me about $100 for a long-arm desk version with a custom logo with a 2 inch diameter - it sounds pretty good, mostly because the production time is two days and they can get it to me on Monday if I order tonight.
I have two seals that I'd like to have, so I think I'll try out the middle range that you have, in addition to this one from eRubberStamp.
I'm looking into finding a press that can make me nice grade lithograph prints, so that I can finally get serious about getting my art out there.