Glad to see Frenchy & Robin have joined the party!
Robin, I don't remember who it was, but somebody posted some pictures in the database that looked like a wagon-wheel type arrangement made with slate pavers, stood on edge to create divisions between semp groups. You could maybe use some of those curved building stones (like people use for fire pits) to make a ring-shaped raised bed, then use rows of upright pavers for "spokes" and put something fun in the center for the "hub." (birdbath, obelisk, strawberry pot with little semps...)
If Lynn runs short on any that more than one of us want, we'll either split a group of offsets (she generally packs them in multiples, 2-4 I think) or find another way to juggle (eg, everybody missing one, instead of one person not getting 4 varieties they asked for). I know you are all good about letting me mess with the final numbers!