Decided to go with apple espaliers instead of citrus hedge along my chick run. Been wanting to experiment with espalier for a long time so let the fun begin. :)

Question is.... What would be the best rootstock to use. Is M-111 likely to be over vigorous and required a ton constant pruning? or is M-9 the better choice? M-7 suckers like mad on my other trees so I am avoiding that rootstock like the plague!

The area is 24' long and trees have about 7' to grow up to. Are four tiers appropriate or would 3 be more realistic?

Thank you all for your time and opinions.

Jennifer