Congrats on receiving your new trees. I just got a Black Gold cherry from Raintree about 2 weeks ago. I sawed it off at about 3 feet high, and removed all the buds below 2 feet. The remaining buds are swelling up nicely and I believe they'll leaf out within the next week or so.

If I was planting in a container, I wouldn't have any qualms at all about lopping the top at 2 feet, or even just 18 inches or 1 foot, as long as there's a few buds below there to allow good branching out. If the nursery rubbed out all the lowest buds (which I think is possible) then I would be more reluctant to lop it that short. But assuming there are a few, then go for it if you wish. I would expect VERY vigorous growth then because the more you take off the top, the faster it will want to grow to catch up with the root system.

I don't know anything about rooting cuttings or if it is even possible. But like you've alluded, these would then be seedlings and you'd have to consider whether you wanted to graft them over to another rootstock. If not, it will be a few years before they fruit, and the trees will be enormous >10 years from now.

Have fun.

Looks like over at DWN they recommend knee height to begin with. I measure approx 24" to the top of my knee. I think I have generally chopped at 30 above the union.

Here is a link that might be useful: Knee Height