I would not use a fuel filter for "atf" or a hydraulic type system. I'm sure some info on this is available (not by me I dunno) but a metal canister fuel filter does not seem to be where to start looking..
In hydraulic type systems I have seen most use spin on type oil filters with higher filter type media... However with the ps unit I would assume a inline filter such as those used on transmission lines would work great.. a few bucks saved here using the wrong filter for application could be very costly as if you were replacing Honda ps parts.. I know you don't have a honda, but you would still be replacing parts, and it would not be fun, cheap or warm this time of the year.
on edit see I told ya I didn't know what I was talking about as audijunk has already done just what you are talking about it appears.