My Building society decided to de mutualise so I went for the Garmin GPS 295.
Over GBP1000 admittedly but it's basically a portable Garmin430: same screen, glorious colour and with 12 satellites it never drops out.
Got me to the south of France and back no sweat last week. (of course I did look out of the winder now and again.)
Basic model has enough roads to get around but for more bobs you can get full road map facility. (waste of dosh IMHO)
Chews batteries though so if you haven't got a fag lighter socket in your a/c forget it.
Happy flying.