Have a look at Hansen Pole Buildings - have been very impressed with their company:
www.hansenpolebuildings.com
Also have a blog on all things pole building:
https://www.hansenpolebuildings.com/blog/
If you send them the dimensions you are looking at they can get you a comprehensive kit price...
I have a JLG T350 (a little lighter than your Nifty at 3400lb vs 4400lb) and move it easily with our B7500 with FEL and R4 tires, but out property is pretty flat.
I have a 2" hitch receiver welded to a 3 point quick hitch so can keep it level without problems.
Second that the lift tires...