Wow. Some great solutions!
Cost is important, but I'd rather do it right than have issues down the road that require me to fly somewhere and fix it.
I know several old PC's (PIII's) can easily support web browsers and offer an acceptable end user experience. However, PC's generate heat and can crash... There is a good chance I will need several of these, so I really don't want to rely on used eBay components.
I like the "thin client" approach, but it sounds complex...
I am going to work on some different specs/scenarios over the weekend.