I picked up a Garmin eTrex Legend off of Amazon for $120ish. It comes with the serial cable (For the GPS side), and it does WAAS. Im too far north to pickup either of the WAAS sat's, but if more get put up there, it'll work.
I've been really happy with the unit, and it is nice to have a standalone GPS if I want to take it camping and dont want my Zaurus out in the woods. It's also nice to not have a huge growth sticking out of the CF slot.