Here is some helpful info from the pros. Regarding particle size and surface area. Talk to them to get the right info.
http://www.aeromotiveinc.com/tb.php?id=10
Modern FI cars use filter "socks" on the fuel pick-up tubes for the in-tank pumps. (nothing stopping us from using pick-up tube type "socks" when using in-line pumps either) and another filter pre-injector filter. The socks keep the big particles out and dont restrict flow (short of filling tank with topsoil). Many modern cars can go over 100K+ miles before a fuel filter (post pump) is clogged to the point of reduced flow/performance and needs a change, depends on design and amount of dirt sent into tank or corrosion by-products in your fuel stream.
Here is an example of in-tank fuel socks used in the 60/70's for pick-up tubes with external fuel pumps for use with a 3/8" pick-up tube, suitable for street use but not for racing however.
For even more options, NAPA has a big choice (241) of fuel pump strainers that you can connect to a pick-up tube in the tank with a little fab work.
http://www.napaonline.com/NOLPPSE/(S...=0&Ntk=Keyword