The VZW 700WX does not have GPS ability, never has (like just about all other VZW devices). As far as relying on a custom ROM to enable this, that's not going to happen, as there's very few custom ROM's available for the 700WX. There's Ebag's customized WM5 and nightraven's WM 6.1. I know of no others. Look over here...
http://discussion.treocentral.com/tr...stom-roms.html or at any of the several stickies on this site.