No suggestions on a contractor, did my own a couple years ago including replacing the tub with a custom mudded shower.
If you do find a contractor, make sure they really understand proper waterproofing.
This website has all the information you could ever want, and even if you are going to hire someone, it helps to know how it supposed to be done.
http://www.johnbridge.com/vbulletin/...isplay.php?f=1
So many contractors think that because they can slap up some tile, they can install a custom shower, and unfortunately, the waterproofing issues usually won't show up until the contractor is long gone. Common failure points are the curb, benches, niches. So many people seem to believe that caulk and cementboard = waterproof.
