[Neil Martin]

My only worry with anything more dwarfing than MM106 would be the lack of anchorage unless you plan to permanently have it on wires, but that would detract from the overall effect I feel.

Of the Malling rootstocks M26 is the smallest recommended for espaliers but is recommended to be permanently staked. MM106 is the next (readily available) size up and doesn't need staking, it is also available with a large selection of varieties if you are buying maidens.

Brilliant, thanks.  Do you have any similar recommendations for pears?

I know that this is an old thread but I would like to know how you got on with your Belgian fence as I am just starting mine. I also live in Scotland and have bought 9 trees to make a 20ft  Belgian fence. I have never grown trees before but had success with trainingredcurrants and gooseberries so wanted give it a go. I have bought an equal mix of apples, pears and plums. I've built my structure and am ready to plant. I now think the plums might be a mistake. They are on St Julien rootstock. In the end did you add plums to your fence? Did it work?

[Yorkie]

Unfortunately it's been a while since Trikidiki has been on the site, so I suspect you won't get a reply to your questions.  I see you've started your own thread, though, so hopefully you'll get some replies to that