What would you use for a reciever/antenna?
You can buy a basic hand held GPS for a little over $100 (maybe less on sale) that should work anywhere in the world. It will give you basic position data and calculate speed. You can program waypoints and routes also.
Check out boating stores/catalogs, like West Marine or Boater's World, they have quite a variety.
If you spend a little more you can get one that allows you to load maps/nautical charts for specific areas. Then the display will show you as an icon on the map in addition to all the normal lat/long, speed, altitude etc.
My handheld has those capabilities and cost @ $400. The charts load for the Chesapeake Bay cost another $150.