Sometimes, I think I sound like a broken record, but the Tiger River line will fit your dimensions, and may be in your budget. Some of the Artesian tubs may also in your price range, but I haven't heard too much about them and can't comment in detail on them. Thier Saba model fits your dimensions (Have you allowed room for a cover lifter?)
I belive all of the Caldera tubs will fit your space.
I had an old TP tub, and when the pumps cycled on it was loud enough to not want it close to a window. If you do look at some of the TP desings (Artic, Coleman, Jaquizi) listen a bit to the pumps and keep in mind they will cycle on when you are not using the tub. Perhaps they have gotten quiter -I cant say-, but would have you keep that in mind when shopping.