From your user name I'm guessing that you have a 75? If so there are not many trans options out there. The 76 and newer motor has a different bell housing design so everything that fits it would not fit a 75, and the motor mounts are substantially different so it is a large project to swap a 76+ motor into a 75 or older.
If yours is 76 or newer there are several ways to get a 5 spd stick in there, and I might have an idea for an auto that would have over drive. The Isuzu Impulse up to 1989 had an auto trans as an option and I believe it did have OD. I'm not sure how much that trans relies on the computer in the Impulse though. Might take some creativity to get it to work.
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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)
MEPR: Man, my 4x4 makes all other LUVs look good