I gave up on deco like that. But a few years ago there was a website that had a how to on a GREAT pool table and aquarium and even a wide screen tv (one was glacial staffs and the other was cloth). This was back before UO acutally gave us them in game. I have tried to google and see if I could find it but am unable too, maybe this will remind someone who has a better memory than I do. It also had a how to on things like a toilet etc.
From what I remember it used a combination of cut and uncut cloth dyed a blue color for the aquarium and whater you chose for the pool table. With the uncut cloth placed on the floor and the cut on top of it. You raised the cut cloth first then raised the uncut cloth. When you got them both to the level you wanted you could play around with the difference in the 2 to give it some depth. The legs were standard table or stool and were dropped under the cloth when you got them to the right level. The rails were 2 different kinds of staffs, one for E and W side and the other for N and S. Like SPA above I also used dyed wool for the balls, but with the large gems being available these days, that could be a possible route.