Large a/c bus from Ekkamai 131฿ or you can book a taxi which is approximately 1200-1500฿ and takes about the same amount of time, 2-2.5 hours depending on traffic.
I suggest you use Agoda for looking at or booking a hotel. You can use the filter option to pick and choose what options you want/require. I’d say you won’t have to worry about the hot water as almost every rental there will have it.
If you haven’t been there before, I would say 5-7 days to get the feel of the whole of Pattaya. If you’re going to party and drink only, a couple of days would do. If you get bored, jump on a boat over to Koh Larn for the day or stay a hour there.
I took a look at their website and it doesn’t mention anything about helping with extensions. I’m pretty sure this is the same company in which I’ve used for doing border bounces and visa runs.