When I was laying out my fuel system, I spoke with a support engineer at Aeromotive. With either an electric pump or a mechanical pump (RobbMC in my case
RobbMc Performance Products - Ford FE 1100HP Fuel Pump) they recommend a 100 micron filter out of the tank, and a 40 either before or after the regulator (there are trade-offs either way). I went with these
http://www.summitracing.com/parts/ae...Fcue4Aodu1AAvg because they are high quality, cleanable, and look good, and you can change the element from 10 to 40 to 100 in any filter housing.