Etrex Legend - released in 2001
Etrex Venture - released in 2002
The Garmin Etrex Legend & Venture are the only 2 of the Etrex series is that will take serial NMEA in and display it as waypoints.
This means it can be connected to a Kenwood or VX-8GE and display the position of other APRS stations on it's screen, and the radio can use the GPS unit for it's location & speed.
Other units of the Etrex series can be used as a GPS for the radio but won't display stations on its screen
(N.B. some of the newer Etrex do no longer have serial out).