Hey,
Welcome to the (gps) club. Basically, you're in with whatever you want to spend/lose on the hand. I broke 2 CF card gps receivers before I smartened up and went Bluetooth. If you're in a car, you can lay it in the front/back window and get excellent reception. If you use a mouse or CF receiver, you're limited by attachment to the mouse or you have to hold the PDA forward for line-of-sight on the satellites. It's all on you.
The BT GPS receiviers are about $80USD now. The kick in the pants will be the decision on the brand of software to run your GPS information. That's where it gets hairy. I have used perhaps the most widely criticized version (Pharos - Ostia) for the past 2 1/2 years. I'm looking around for a version that displays 3D graphics that give a 'heads-up' type display of what's coming at you. The 2Dimensional views are passe; they work, but you know.....you've got to grow & go.
p.s.
I use mine for driving, hiking, hunting, boating, fishing, and geocaching.
Good luck,
ldjohn55