Espaliers Along a Hedge?

We recently moved into a house (our first house!) with medium-sized garden enclosed with mature beech hedges. I've always dreamed of lining my garden with fruit espaliers to maximise both space and food—apples, pears, figs, cherries, medlars, plums, etc. 

Is it possible—or even a good idea—to plant espaliers along a hedge? Obviously there would have to be posts and wires or something for support but what about keeping the hedge trimmed behind/light issues/anything else? Has anyone tried planting espaliers along a hedge? 

Notes: One hedge is south-west facing and an absolute sun-trap while the other is north-east facing and shaded for most of the afternoon. • The soil is dense clay.