What is the size of your planting area? Apple tree sizes go all the way down to dwarf. Should you decide to plant two of them will there be adaquate spacing between them. My general advice to planting any tree is this... When you plant it, try to visualize that the tree you are putting into the ground is full grown. Too often, this is not done, and that little 5 footer that had plenty of room when just placed will in a few years have no room at all. As far as varieties for the type of soil you have....well my experience with this fruit goes as far as those in mom's apple pie.

If there is a variety you particularly like put it into Google and add "pollinator" and you should get a list of varieties that are recommended. M27 is a dwarf rootstock and a tree grown on it should not exceed about 6 feet. To get an idea google apple tree rootstocks and there is a diagram showing the relative heights of the whole range.
If possible I'd go for ones that flower later rather than earlier to avoid cold wind and frost on the blossm. as much as possible.
www.orangepippintrees.co.uk › Help and Advice
for lists of pollinators.

A specialist grower, such as Ken Muir, would also offer good advice, and have a good selection of varieties to choose from.

Growing apple trees is not as straightforward as you might believe, not least because of the pollination aspect (some apple tree varieties need 2 different ones nearby to set fruit). You don't need to grow them as trees either. Apples are often trained against a wall or fence as espaliers where space is at a premium.

Good advice on growing apples can be found here.

http://www.orangepippintrees.co.uk/articles/how-to-choose-an-apple-tree-for-your-garden-uk

If any close neighbours have an apple tree in the garden, it will act as a pollinator for yours.

Thank you all for your responses :)
A lot to consider, I will let you know what I decide on