Welcome to the forum my friend
I would go with a BU-303 USB gps these are standard among the mp3car community and are a pretty good price.
For software i would reccomend Destinator 3/Map Monkey
check in the software forum then the sub forum support software then you will see the Map Monkey forum
Also i reccomend u check out Freedrive its the same as map monkey basiclly but the GUI is totally different