First, the claim that a larger fuel rail will compensate for small injectors makes no sense to me -- that's like saying I put one titanium link in this chain, so it's stronger than that other one with all steel links!?!

Second, I don't think you have enough injector to comfortably run 20psi -- others can confirm.

Third, here's my fuel system diagram. The particulars may vary, but the basic layout is generally the same. Basic stuff to remember:

The lift pump must be able to supply enough fuel flow to match your needs at WOT, at zero PSI fuel pressure.

The pressure pump must be able to supply the same volume of fuel as the lift pump, but at your base fuel pressure + max boost, which is why the pressure pump(s) is (are) usually much more powerful.