Ipaq 3115 GPS System Advice Pls

Would like advice on purchasing a GPS system for my newly acquired Ipaq 3115.

Newbie to the PDA scene but I would ideally like to purchase a complete bluetooth system with software and I drive a Ford Focus with a heated front windscreen, as i've heard that the elements in the w/screen can have an effect on the signal.

Heard a lot of good stuff about the Tom Tom software, but after reading some of the threads on this forum..................Is it really that much of a nightmare to register the product.

Thanks

Mark hawkins