Yes, I've had great service from Adam's Apples in the past, and also Ashridge Trees.
It's a false economy just to buy any old supermarket tree. The ones I saw for sale this year had been dug up far too soon (still green leaved, as winter arrived so late this year), and didn't have any information on the tags about their rootstocks or pollination groups. That makes everything far more hit and miss, don't you think?