Fleetguard FS-1212 Diesel Fuel Filter???

Phoenix, AZ.
I have an'03 Dodge/Cummins and installed a Dually Depot, 115 gal. aux. fuel tank in the bed. the tank came with a Fleetguard FS-1212 fuel filter. My understanding is that they are 10 micron filters. I believe Caterpillar has 1-2 micron filters. Do any of their filters fit in place of the FS-1212? Would there be any "flow" problems with a 1-2 micron filter since this is probably a denser, more restrictive media? Are there any other low micron level filters that I should consider? Thank You, for your help. Joe F.(Buffalo)