After getting sniped on an eBay auction for the old GW watcher bits, I finally found something worth giving a try at Auggie's Games. They arrived yesterday and –I have to say– I am pleased. Check these bad boys out!
Look out, Strider!
All six plus S&H was about $25. They are pre-painted, but look pretty darned good, IMO. I think I may try to make the bases more "watery" (and I may add a color coded dot to each base to keep the pseudopods straight during combat) but otherwise they are exactly what I was after.