Choosing A Hospital In Bangkok

I'm going to be in Bangkok next month and I'm thinking about having a test done while I'm there (sleep study). I've been to Thailand a few times before, but I've never set foot in a hospital there, so I've got a couple of questions I hope you guys can answer. I sent e-mails to 4 or 5 of the hospitals with sleep centres but I only got one response, and it wasn't that helpful.

1) I'd like to go into the hospitals to take a look at their facilities and to talk to someone who's familiar with the testing procedures. Is that usually acceptable in the foreigner-oriented hospitals in Bangkok?

2) And what about prices? Do they tell you a price and it's firm, or is it usually possible to negotiate a better price?

Thanks