Agree M26, needs permanent support, any more vigorous and you will def get a lot of shading or have to do a lot of hard pruning, but even they can be quite vigorous depending on variety of apple. Website orange pippin gives an idea of the growth potential of each variety combined with each rootstock. Depending on length of the wall cordons could be good, and be planted every 2 and a half feet if necessary, better angled but can be grown vertically. I have had good supplies mail order from Adam's Apples and as said price is quite good. Andrew Lear (appletreeman) does not think you need to remove all apples in first year. He is moving into apple supplies. I would love to grow stepovers round my beds, think it would look great