Hi Marcus, I dont think you have to go for the Ro-Man booster pump, most booster pumps would do if they are rated correctly, ie, do they give the right flow-rate at the right pressure? ( too high a flow rate on the pump would either damage your RO membrane or damage your booster pump itself. Too high a pressure could also damage your RO membrane. Check the specs for your RO for flow rate and max psi, if you can get a pump to match, go for it.)
The booster pump goes after the prefilters and before the membrane. You can fit it before the prefilters but there's a greater chance of the prefilter housings springing a leak.
Another option would be to add a 2nd membrane to your Ro, that'd boost production, especially combined with a booster pump.
Tim