Any tips on building bathroom furniture out of MDF to take a semi recessed basin and a concealed cistern with a back-to-wall toilet pan.

Any tips for cutting long straight edges?

What about finishing after. It needs to be a fairly robust finish and as waterproof as possible. I would use MDF primer and then a couple of coats of satinwood topcoat. Would probably hire a spray gun to get a better finish.

All tips gratefully received.

Ben