Right now, the only thing that I know of to do front digs is a rear D-shaft disco. Rear digs are easy, twin-stick.
Marlin has been working on a gear drive t-case for many years to do front digs but he keeps running it to some problems of some kind or another. About 4-5 years ago, he took me for a ride with a prototype front dig T-case but something did not work the way he wanted it to so he put it on the back burner.