Hi all. According to the "Royal Horticultural Society Gardeners Encyclopedia of Plants & Flowers" the most common trees in England are;
The Common Oak - Quercus Robur
The Ash - Fraxinus Excelsior
& The Beech - Fagus Sylvatica
All large trees growing well over 20 metre plus.
Alas, I am not a master of all things Arboreal.....but that's what they say. I thought the Sycamore would be there too. I am from the North East of England though, we really need some posh git from the Home Counties to set the record straight

. You should see some of the trees in County Durham, they look like skyscrapers relative to this 'Bonsai' affair lol.
I agree that it is very important to get this right however, as it has to look like England. These are of course all WIP people, so give them a break.
I would say the Royal Horticultural Society would be the definitive source on these matters, without doubt.....So check them out!