GPS Navigation/Tracking

[all-mtr-teg]

I'm looking at getting a GPS navigation system for my car. I was also looking at getting a tracking unit as well. Any recommendations on a good unit? Are these any good?
http://www.brickhousesecurity.com/car-vehicle-tracking.html
http://www.brickhousesecurity.com/covert-gps-tracking-navigation.html

[SOHCinWA]

I would check out www.compustar.com