Does anyone have any personal recommendations for local companies which carry out this work? I only need 2 small pieces, about 1 square metre each, cut to accept bathroom sinks.

I was actually given an approximate location, but buggered if I can locate them

There is a company on Sukhumvit.......they are on the left shortly after joining from the 36 road

I know that they are well priced, and popular with the local builders

I have used them a few times

Marble is fine if all you want to use it for is pastry making, but it is quite porous, and would absorb red wine stains, etc. Granite is far more suitable. Many granite/ marble dealers / fabricators on Sukumvit, Eastern side, between Central and Trepprasit.

Marble is also not doing well with acids, i.e. vinegar or lemon juice

Star Decor on the corner of Prasert Manukit (Kaset-Nawamin) Rd and the road under the Ekamai-Rahm Indra expressway. Granite is the stone to use for a bathroom as it won't absorb detergents, soaps etc.

Quite a large Granite/Marble place on left hand side going out of town towards JJ Markets.

Almost opposite WhaWhee Coffee. We've bought a lot from them, cut to size, trimmed and polished. They deliver larger pieces for bench tops etc.,

Agreed granite http://www.diffen.com/difference/Granite_vs_Marble

Quite a large Granite/Marble place on left hand side going out of town towards JJ Markets.

Almost opposite WhaWhee Coffee. We've bought a lot from them, cut to size, trimmed and polished. They deliver larger pieces for bench tops etc.,

Is this in Pattaya?

There are marble/granite shops all over Pattaya. Boonthavorn has a huge supply and I'm sure would be able to take care of you.

When we had ours put in, the contractor warned us about the cheaper stuff. It's very porous and stains easily. We've been abusing ours for 4 years now. No stains or marks, even in the Thai kitchen which is used daily and gets all sorts of abuse. Still looks great. We got it from Boonthavorn.

You might try a Google search of "poured concrete countertops".

There are some incredible options if you can find a good designer.