This looks to be a good choice. It can even be powered from the Empeg amplifier control signal due to the low current required. All you will need to do is make an RJ-45 to DB-9 adapter. Oh, and then there is the software!

Try these two sites for purchase. They both show it for $150 US.

http://www.a-nautical.com/catalog_garmin_gps.htm

and

http://www.navtechgps.com/supply/gps16.asp

I am familiar with the latter outlet and they have been around for quite a while.

Good luck,

Lynn