A 24” Fury is small with a 300 Pro XS on a Puma STS. Most run a 25” on that application. Be sure your PVS vents are open and some will run one or two holes. Almost all Puma STS models have a hydraulic plate, raising that helps hole shot, then lower it once you’re rolling as you go on plane. It will need lowered.
A Bravo will definitely help most on hole shot if that’s your goal. Fuel mileage won’t vary much either way and the Bass Cat hulls are more fuel efficient than most other brands. We would think a 26 Bravo to be large on the Puma STS and we have a 25.5 lab style we’ve run here. It’s not as quick and most here prefer the 25 Fury. We do recommend the 24 Fury on 250 models.
If you load heavy, run multiple front graphs, maybe a HB 360 or Target Lock system, and have Power Poles, then we do suggest a 23 Fury on 250 Pro XS models and 24 on 300 Pro XS.