In my old shop, a single stall was all I had as well. I built a gravity feed oil dispensing system just as you are looking for. I went my local sheet metal shop and picked up some misc. pieces of stainless sheetmetal. I welded up two 12"w X 12"h X 12"l boxes. I put a 1 1/2" fitting in the top...
How about getting an old pop machine and just dispensing cans or bottles of your favorite beverages? You can set some up to not charge, you could also have a .25 or .50 charge for them that way there if truely a "fund" for refreshments!!!
I finally decided to stop lurking and join up. Been over on the HAMB for quite a while, and figured might as well join here too. I'm sure I'll become more of aregular, just seems to happen!!! Talk to ya'll later. :beer: Al.