hey_mon,
You will love Treasure Beach. Don't know Katamah but bet it is a great spot. TB is much different than Negril and has it's own kind of beauty and charm. If you want to do day trips you can or just hang out and enjoy the day. I have stayed at Sunset Resort & Villa's and always a lot of Canadians stay there. The guy who owns the place, Kory South is very helpful so you should stop by for a drink or try their food. Two doors down is Jakes and Jack Sprat two very popular spots in TB.
The Appleton Estate Tour is worth it and their gift shop has some rums that I have not seen offered anywhere else for sale so if you are big on rum it is a fun visit, about 2 hours from TB.

All the best!!