That size pump can deliver from 4 GPM to 10 GPM, depending on the depth to water. I am not sure that is enough to run body sprays by themselves, much less at the same time anything else is running. A bigger pressure tank won’t help. It can actually make things worse as the pump sees the tank as an additional load to fill. Check the flow rate required for the body sprays. If the pump can supply enough for the body sprays, you can make this work with a Cycle Stop Valve and a 4.4 gallon size tank. If the pump can’t supply enough water, you will need a bigger pump or a cistern tank and additional booster pump to be able to use as much water as you want.