I wanted to post a follow-up to this... I ended up building the
homebrew filter and it worked perfectly - totally eliminated the fuel
pump noise. It cost less then twenty bucks in materials and was very
simple to assemble and install. Here's a link to the directions I
followed:

http://97vette.com/sporttrac/rfi_fix/rfi_fix.html

A little specific info if you have a Tribute/Escape: to get to the
power leads, simply remove the driver's side back seat (it slides
forward) and pull back the carpet. There's a small square panel that
easily unscrews to reveal the leads (pink and black). There's plenty
of room within this panel to store the RFI filter. Couldn't be easier!