Hi Sabrina,
I have similar problems - a very high and exposed site.
The advice I have been given is to get as sheltered a site as possible (plant a fast growing hedge or walls)
Choose a vigerous root stock as they establish better.
Choose a variety that has the shortest time between flowering & fruiting (that way the blossom survives late frosts and the fruit have a chance of ripening before the early frosts & wind gets them.
Another option may also be to grow them in a polytunnel (with the roots outside), trained to suit the space - cordons or espalier or fan shaped. But I think with this method you might need to intervene to ensure pollination occurs. Also look out for self fertile varieties if you are only going to have one of each type of tree. I'm still trying to figure out what I need in terms of what will grow and what will pollinate the varieties I want because of lack of other fruit trees in my area - maybe I'm a bit thick though.
I was put in touch with John at Butterworth's nursery in Ayrshire through my local orchard group, he was very helpfull and might be able to recommend some varieties for you.
http://www.butterworthsorganicnursery.co.uk/http://www.clydevalleyorchards.co.uk/Might be worth checking if there's one in your area ?
Good luck with it - hope I've been of some help.
Karen