I don't know if it has everything you require.
but all the Marriott timeshares have a nice gym. So did the Renassiance hotel next door to SW.
I already mentioned VWL on another post to you. You can rent points from a DVC member and make it close to what you were paying at CBR. at cheaper alternative is SSR, it also has an excellent gym.
I am sure the new deluxe hotels have a great gym - Gaylord, Ritz-Carlton, J W Marriott (the last two are also close to SW not WDW). Gaylord is close to WDW.
I think there is a Gold's but I can't remember where I saw it.