What size pots for 5-7ft trees?

[NaptimeRocks]

I've just bought some fruit trees (apple, pear, cherry and plum) that are going to be delivered in a few weeks. They are going to be delivered at about 5ft and grow to 6-7ft. Apparently, I can plant them in pots so that I can put them on my patio, but what size pots do I need? Presumably rather large ones!!

Any advice much appreciated!!

I would also think quite large but not too sure how large.
Can you ask the nursery who are supplying the trees? They should know...