I bought a Garmin eTrex Legend ($130 at Amazon, and it comes with the serial cable) for use with my Zaurus. I didnt want to get a CF GPS because they are HUGE and this is nice because I can use it without the Zaurus.
I've really enjoyed it, and have it hooked up in my truck using Zroadmap/Flite to give the location. Havent got qpeGPS to work yet. Im on OZ 3.5.2.
Zroadmap uses the US Census Bereau TIGER maps, and they are a couple years old.
qpeGPS should work with any scanned/downloaded/hand drawn/chicken-drawn map, you just have to set it up correctly.
I made a larger map using Google Maps and just stitching the pictures together by hand.