You can just get a facet solid state aftermarket job, you can get them with all sorts of pressure settings. They are usually available at repco etc, for around $80-100 I have one at home that is rated at about 10PSI, and would do the job really well. But you also need a fuel pressure regulator, as SU carbs like low pressure, (not low volume).
Ideally set it at 2.5 PSI. How do you tell the pressure? Easy; fit an inline fuel pressure gauge unde the bonnet.
I am about to sell the Facet pump and the holley fuel pressure regulator as I have gone back to 'period' style with an SU pump and a filter king regulator. Send me a pm if interested!
Cheers
Matt