Espalier Trees

Well not sure where you are, but I bought mine locally from a nursery that has all the old kinds. I try to buy local because of the difference in soil from area to area... I have bought from here a few times and all very good stock and I went for a couple of old variety apple trees and Pears and all very good croppers.
http://www.lodgefarmtrees.co.uk

My friend has bought some from here and they have taken nicely..
http://walcotnursery.co.uk

 

Best time to plant bare root plants is in the autumn. Pot grown you can plant anytime (but cost a lot more)

I planted some in Nov 2012 as per this thread:

http://gardenerscorner.co.uk/forum/threads/apple-recommendations-please.46726/

I ended up planting "1 year whips" and have been training them since, this is my first year with apples and they still only have 3 small 'tiers'. You can buy them already trained but they are £50-£60 a go.

There are a few threads on here about getting fruit trees, Ashridge Trees always gets good reviews.

 

Once you start researching nothing seems straight forward!

Go to a good local nursery like Marley says, they will give you advice on Pollination Groups, rootstock etc etc.

 

You need just one other different cultivar that flowers at the same time nearby, maybe a neighbour has one, otherwise plant one from this list:

http://www.orangepippintrees.co.uk/pollinationchecker.aspx?v=1102