Yes..it is possible but unfortunately espalier doesn't suit stone fruits. All the hard training forms involve lot of pruning which stone fruit trees doesn't like and as they don't grow fruiting spurs as apples and pears do, stone fruits are dependant of having plenty of growth to produce useable quantity of fruit. Hard pruning also makes them prone to many diseases.
So basicly if you would grow them in espalier of other such a trained form..you have lot of work ahead with need of skilled pruning and not much rewards for the return.
You could grow fan shape against wall..but ideally you would not prune anything that has already matured into 'wood'...but keeping pruning just to early summer shoots that are still soft and tender and piching them the soft tops with fingers. Those tip 'wounds' will heal quickly and not being such a risk for 'troubles'. With fan you can also 'get away' with not so hard pruning..as you can bend some of the growth against the surface instead of cutting it off.
