Maybe, I'm way off here,
but the non-returnless systems vary the voltage to the fuel pump to get the deisred pressure, correct? hence no return line.
What would happen if you used a larger fuel pump, some resistors and capacitors,and a MAP sensor, along with a comparator circuit(simple circuit and chip) hooked to the MAP sensor as the Voltage input to allow it to switch the ouput to the fuel pump based on MAP pressure? Then you could plumb the power supply to the fuel pump "inline" with a series of Resistors, ie so at idle with no boost youd get a lower voltage to the pump, thus giving you the same Volume of fuel as the stock pump, but when you add boost, it would slowly(ok incrementally.., but if you added some capacitors it could ramp the discharge to smooth it out)decrease the resistance, increasing the voltage , thus increasing flow output, and thereby increasing the pressure to the injectors??
Anyone have any ideas on this? Brad, Chris, Terry???
If you give me the ideas i can probably draw ya'll up a circuit for this... I'm a logn way off from a supercharger(or turbo even) and might go nitrous instead.. but... jsut figured I'd offer my assistance.