I got adapter fittings from Earl’s for Tracy’s pumps and plumbed them in parallel.  They don’t allow backflow, so you don’t need check valves.  I takes a lot of fittings by the time you go from one line from the tank, split to two pumps, back together, put in the filter, and the pressure sender block.

 

I’d just suggest being a little selective on the filter.  Downstream from the pumps I think you’d want less then 50 microns, rated at more than double your max expected flow to allow for some blockage; and I think in the long run, one that has a cleanable element.

 

K&N made some nice filters that they have discontinued.  Same for Edelbrock.  I ordered filters three times before I actually got one, and ended up paying over $100.  There are stock filters that have AN fittings; you might have to search or find someone at a parts store that knows something.  After I bought mine I came across one, but now I don’t remember what is was for; maybe Porsche or Mercedes.

 

Mine is Peterson 600 series, and I bought it from Motorsports Supply in Colorado; about $105.  Probably more filter than needed, but hey, it’s for my airplane.

 

Al