is it possible to get....(apple related)

A apple tree that grows no more than 8 feet tall and the same in width. we are planning for next year and are converting a bed entirely to fruit, its my understanding that apple trees will need planting very soon for a good start for next year. Could any suggest, what sort,were and general idea's

It will pay you to do some research into root stocks they have a direct influence on an apple trees vigour and size.
I used to know them all but can't think of whats what these days 

M6 gets to about 6 ft.
M9 gets to about 8ft.

If the type grafted on is a triploid then the resultant tree is bigger.

Both need staking as support throughout their lives.

The get them to the width you want is a pruning exercise. Allow 4-5 branches to grow off and prune/train the tree into an "umbrella" shape. Best go look at trained trees to get an idea.