corn will beat the heck out of you for manual grinder....
I have used the electric wonder mill for wheat and it worked well. I had ok results with corn, but never could make good corn bread with the dried corn I could find.
The best rig would be the big red manual grinder (grainmaker) with a home made power attachment. Why? It can make peanut butter and corn meal.
However ,you would need a power attachment would be a small electric motor with fan belt drive if you are doing much more than cracked corn.
One required accessory - sieve for flour