Sorry about your friend. But we need more information. Where in the world are you located? Somehow I’m guessing U.K.?

Where are you located? And what do you consider to be a "good, strong size"?

It would also help if you could provide some photos of the area where you intend to plant and a few more details.....soil conditions, ease of watering, sun/shade, etc.

As has been said, much depends upon your zone and the local conditions.

Do you mean a tree that is large/robust for a flowering tree or a large tree that flowers in a showy way?

Wow! Thanks for the speedy replies!

i Live in the northwest of England. A place called Bury.

when I say a strong size tree, id Like something that will grow quite large eventually. Like the height of a lamppost. I have very little knowledge of this stuff. Sorry about this. Maybe I’m being too optimistic when I say a large tree but with flowers. I sometimes see trees that have pink or white flowers on them. Sorry I don’t have any pics of the area to hand. I could maybe get from from google maps

This is all I can provide at the moment.

a pic from google maps. I’d like to plant my tree to the right hand side of the pic. Where the treeline starts towards the river