In your area you could move them as soon as the soil is dry enough. Sooner is better than later. I'd think they'd do fine with a move.

No water until they start to leaf. Then one heavy irrigation (2 feet down) in area of trunk (about 5 gallons drip applied or make a ring of soil around the area of the trunk and fill with water). This is newly planted. For the first 8 weeks after first leaf keep area where roots are growing moist. After 8 weeks let the ring keep water out--though maybe that won't work for flood irrigation--and water up to four feet out and three feet down halfway in between irrigations. After the first year, your flood irrigation schedule should be adequate except in the most extreme dry heatwaves, especially if the ground is heavily mulched out to four feet with wood chips around the tree; but not right up against it. Testing should be done with a 3-4 foot soil probe. This post was edited by Fascist_Nation on Sat, Feb 8, 14 at 23:28

That looks like heat and water stress damage. You may not be watering deeply enough. Try a longer slower soaking. The damage isn't serious and the trees look good. I have mature pear trees looking similarly damaged from 100F heat.

Toka is a good choice. I would consider grafting some other American and/or Hybrid plum varieties onto Toka in case Black Ice doesn't pollinate it. It is pretty easy to learn to graft plums and be successful in the first year. Next winter search online for scion wood sources, then graft in the spring. These varieties might be best for pollinating Toka: Wild American Plum (Prunus Americana), South Dakota Plum (another sport of Prunus Americana), Shiro, Superior, or other American/Hybrid Plums. It is possible Black Ice is fine, but the more the merrier. Honeycrisp will also need a pollinator. If there are wild crabapples near you they should work, or you can graft branches from them or other apples onto Honeycrisp. Wrap the trunks in screen or something to keep rabbits from girdling the trees, especially in winter. You should protect the trunks up to 18" above the expected snow line. If rabbits are present, they will girdle fruit trees (especially plums and cherries) every time.