P/N 30945 will have 2 bare wires to power the receiver and a DB9 connector to go to a laptop or the Ipag.  Yes it will work with your 4 wheeler.

What software are you planning to use on the Ipaq for mapping?  I am not aware of anything that will let you map A/B lines on a PDA.  You can probably map boundaries, but they will more than likely have to be converted to the correct file format in some desktop software.  You have not said what display you are using and that determines what file formats you need.