GPS for old ROW exploring

Could anyone recommend a GPS receiver that is good for displaying long-abandoned rights-of-way? Thanks.

I use the Nokia N800, with a bluetooth GPS receiver (any one of them should work, but I use the WinTec WBT100), and Maemo-Mapper. Into Maemo-Mapper I load GPX files from http://www.rutlandtrail.org/list.cgi -- which only lists New York State railroads, but I have already entered a few Pennsylvania railroads, and I'd be happy to figure out how to make it list them for you, and to enter other PA railroads at your request.