Kathy,
How about growing the trees as cordons or espaliers? Take up little
space and can be used to edge the plot. The pruning is done in the
summer, so a pleasant job. Can start with a maiden, 1 year old tree.
Going with something on a M26 or MM106 rootstock is the best choice,
unless you a planning on having a Bramley or other triploid cultivar,
then go smaller rootstock. Also do not use a tip bearer, such as
Worcester Pearmain or Irish Peach, as cordons, as you will always be
cutting the fruit buds away.
Clifford