Buying Penjing Pots/Slabs

It is very difficult to locate large pots for Penjing. I'm somewhat flexible, but I really would like to find the classic white marble with the small raised lip/edge.

Does anyone have a good source in North America?

Thanks

Jim,

Thanks very much. I spent hours and hours searching. This is exactly what I want.

Take Care
matt

As noted before, The Monastery has some white marble slabs. Depending on where you are, I have some left from previous escapades. I am in VT and if that were convenient, you could pick them up here. I am loathe to ship large items as they seem to end up arriving in pieces.
I have basically one each of the following:
19" Rectangle
30" Oval
39" Oval
44" Oval
51" Rectangle