Last time when I booked my hotel in Phuket Thailand, I made my booking from http://www.hotelphuketthailand.net , This website provides a great discount rate for most hotel in Phuket. I stayed in Centara Villas Karon for 2 nights at pool villas It was a good hotel and good service. I would recommend this hotel to you.
However this hotel is on the hill not the beach (between patong and Karon). You can see the sea view from your room but you can't swim in the sea. It's ok for me because my villa has a pool inside. Also hotel has a nice swiming pool for every guest as well.
If you really want to stay on patong beach then you also can find many beach hotels from this page http://www.hotelphuketthailand.net/phuket/patong-beach-hotels/.
Hope this help.