Watersports west in largo florida has always had the relacement bladders I need. They normally offer me stock or after market brands too, so they must carry both.
I dont know the phone number right of hand, but I think you can get it from their website at http://www.watersportswest.com
. Their website sucks but their service is killer. They drop ship to me the same day I call everytime. I always get my stuff in a coupld of days and I'm not even near them.