So, I've got gobbs of fencing all over my property, and I'm itching to plants fruit trees, grapes, berries, etc.

I'm thinking espalier planting/growing is the way to go.

I live in zone 6 (SW IN).

I was hoping someone with experience in this dept could give me some recommendations for which plants do best on which walls.

I've got walls I can plant on that face all four directions (North, South, East, and West). Got several hundred feet of fences.

I understand some fruits, etc do much better if you grow them on the right wall. I just haven't found info with many details about which ones yet.

Thanks for any info you can pass along to me!

The north wall is least suitable.

The other walls may be equally suitable, what kind of construction are the walls (how much will they reflect heat onto the plants). Do your walls have overhead eaves, and if so, how far do the eaves extend from the walls?

The wood walls are fine for east, west, and south exposures.
You do not mention eaves, so there would be no special watering problems.