Check out Badgersett for hazelnuts. You might want to give a call to talk about the background. They have hybrid hickories that have decent cold hardiness, but if I were planting, I would get the named varieties of pecan listed above.
http://www.badgersett.com/info/hazelnuts
I don’t know anyone who is currently producing grafted trees of the black walnuts. You might talk barkslip into grafting a few for you next spring. I’ll gladly supply scionwood. If you are up to starting from seed, I’ll send you some seed of each of the walnuts later this fall. You can then graft them in a couple of years.
I don’t know actual area so am guessing a bit about your climate. I think you are somewhere north of Sioux City. I worked in Corning Iowa in the winter of 1978/1979 so am familiar with the climate. I still remember -30 degrees with 30 mph winds and whiteout conditions.
There is a thread about black walnut that is worth reading.
and one about pecan