If your tree is on a good dwarfing rootstock then the three gallon container should be fine for a few years anyway.
If it's on a more vigorous stock then you may find it hard to contain it as the root system will fill the pot very quickly. No problem in that except getting enough water and feed into the tree to sustain it.
Wish we could grow that variety over this side of the pond....but our summer isn't long enough for it to ripen properly.
Mind you...if this global warming happens then it may be possable before long.
Vars like Braeburn and Granny Smith are being grown over here now so who knows.