Why would you need an additional lift pump if you have the one on the engine? We have an electric pump in our system with dual Racor filters, but it is only run for filling the filter bowls after changing elements. We can polish the fuel by drawing from one tank and returning to the other through the Racor while the engine is running.
Which pump you would use would depend on how many GPH you want to be able to polish.
SV Laurie Anne
1988 Brewer 40 Pilothouse