You can get the FH valves from anyone that sells FH/BFI stuff. Usually ~$30ea. It is essentially a one-way check valve as far as I can tell so water should not backflow.
Cheap plastic garden hose valve for the empty side (you can find them at any hardware store). http://www.redhillgeneralstore.com/A30078.htm
Also need the W732 adapter for 3/4" garden hose. Install the valve inline btw the sac and 750 pump or on the outlet hose. Cheap and effective.