Mike,
I am not a fan of family trees, they are a compromise for space. In my
opinion, far better to put more trees in on a dwarfing rootstock.
For Pears (and apples) why not consider growing them as cordons, they
are great as their spacing is less 2 1/2 -3 ft. If you by the trees as
maidens, 1yr old, you can develope them yourself and save quite a bit
on plants too. As they can be planted closer together you can have a
greater variety of fruit. Once the plant as reached 6ft in length, it
is generally stopped. The pruning of cordons is much easier than for
bush trees and whats more you can reach it easily.
If you go down the cordon route for pears, make sure that you use
Quince A or C rootstock.
As already mentioned Stella is good variety. The thing with cherries
is they want (the tree has a desire) to be a big tree unless you grow
it as a trained form along wires. There is a nice example at RHS
Wisley.
If you want to grow grapes why not take a visit to one of the vineyards
and see how they grow theirs. You can see the woody structure of the
vine, it is almost tree like on the main stem with the vines coming off
the woody structure. If you visit Wisley they have small vineyard there
too.
Good luck