Any suggestions on a good 4 speed transmission that would be a good swap for the C-6, its a 4x4 with the 6.9l idi?

 

The t19 was the tranny Ford used. But I would go ahead and find a zf 5 speed, and get some fuel mileage out of it.

 

I've looked around and most are out of my price range also I'm thinking about taking the cab of my 98 GMC 2500 because it was my grandpas and putting on the ford frame. Are there any easy ways to set it up before I really start tearing **** apart?