Parker/Racor make a couple of neat kits: The first one looks less expensive, it has a "neat" drain attachment with a valve that 's easy to use; and, it's less expensive than what I have.

http://www.downwindmarine.com/Racor-P510MAM-Fuel-Polisher-p-91003541.html

We have this Racor model (bought 4 years ago) plus a dedicated RACOR filter which the pump feeds through. We set it up with a "T" form the supply and it discharges into the return line -- also with a "T". (We have port and starboard tanks, and I didn't want to set-up a more complicated system for the supply and return.) It draws VERY little current because the pump is a very efficient, but small pump that only cycles about 50 gals a day. We leave it on almost ALL the time whether we're on shore power or under way. We alternate the port and starboard tanks when at the dock every other week when we're not on transit mode.

http://www.practical-sailor.com/blog/Parker-Fuel-Polishing-Module-10096-1.html