100 gpd x 4 is 400 gpd divided by 24=16.66 gal/hr. Does yours now handle about 16+ gal/hr? If not, find out how much pressure your current components will handle, (plumbing, canisters etc.) Then just try a pump that gets closer to that pressure, if it's the pump you might want for what you suggest, all the better, even if you need to restrict the pressure to 100, or maybe 120psi. Then if that fails to increase your production enough just use that pump with the new membranes and plumbing you suggest.
When a membrane is rated at a certain flow, it is input, not out put and it is at a specific pressure. Don't over pressure any component, even 80 PSI can be dangerous if it blows apart and as that psi increases so does the potential damage.
Dave Klish, I recently ordered a 2x6 wood fired evaporator from A&A Sheet Metal which I will be converting to oil fired
Now have solar, 2x6 finish pan, 5 bank 7x7 filter press, large water jacketed bottler, and tankless water heater.
Recently bought another Gingerich RO, this one was a 125, but a second membrane was added thus is a 250, like I had.
After running a 2x3, a 2x6, 3x8 tapping from 79 taps up to 1320 all woodfired, now I'm going to a 2x6 oil fired and a 200-425 taps.