According to the report attached from Aviation Consumer, the big expense of the GPS coupled 406 ELT's is the labor to make the connection from the ELT to the GPS. Looking at Spruce on-line there are several units that claim GPS outputs and some list connection options. The ACK unit looks the price is right unit but apparently they are still waiting approval of some kind. Spruce has them listed but no inventory. It list a street price of $582.00 and has a direct replacement for the ACK 121.5 for $542.00. It also will connect to your GPS but this is where some labor comes into the picture.
http://www.aircraftspruce.com/catalo...ges/elt406.php
Craig at Griswold has already installed several of the Amrei-King 451 and has some very happy customers. If you already have the ACK 121.5 then by far this is the way to go with just the replacement unit. But if you are like me and still have the older 121.5 units without the remotes, this Ameri-King may be a good direction to go. The basic unit is $759.00 and they are approved and ready to ship. Like most of these new 406 units you buy a portable antenna so that you can take the unit with you away from the scene and still transmit the signal. This unit comes with a GPS interface for panel mount GPS.
http://www.aircraftspruce.com/catalo...ngpackages.php
All the new 406 units require a remote switch. Usually purchased as a separate kit.