Hello Jimmy, No! Not picky!
Time to go back to basics and install a pump like this:
http://stores.ebay.co.uk/same-day-dispatch-auto-parts
similar to that originally fitted to the Efi SD1 operating with a 12 volt feed but using a ballast resistor sufficient to drop the pump voltage from 12 volts to approx 9 volts.
It will depend upon how much current the pump draws, but a 1.5 ohm resistor will drop 3 volts at 2 amps. For safety sake try to get one rated for 20 watts.
You can see the wire wound ceramic SD1 resistor thro' the oval hole in this image
Rover fitted this resistor specifically to eliminate fuel pump noise (cavitation) resulting in sufficient flow rate and a pressure maximum of around 50 psi, more than enough to satisfy the maximum fuel rail pressure in the range 26 - 36 psi.
Some owners misguidedly removed the resistor resulting in increased cavitation noise, increased wear and shorter pump life, for zero performance gain, because the fuel pressure regulator just had to work harder to keep the fuel rail pressure in spec.