Remember, you want to keep fuel pressure stock while putting in bigger injectors to give more fuel. You only want to raise fuel pressure on a 1:1 ratio to compensate for the extra boost in the intake.

You'll want the rising rate fuel regulator to do that. What size injectors will depend how much power. 42lb/hr injectors will be good for around 200-230whp at stock fuel pressure.

More than 230whp or so, I'd go for the bigger fuel pump also. The main benefit of a return fuel system is when you're driving hard in the upper rpms where lag is minimal to non existant, if you go from low throttle to full throttle(ie. no boost to full boost), the ECU can't compensate for the sudden fuel pressure change as well as a mechanical system can.

2000 Rio Red I4 Cougar 200whp & 210wtq at 9psi 254whp & 276wtq with NX 35shot WRX TD04 Turbo, Cut Short Shifter, Strut Tower Bar, 17" ZN Wheels, Roush Springs, Starion Intercooler, NX 35 shot, HKS SS BOV, Full 3" exhaust,StreetFlight Chip