Where to buy trees in the UK?

I want plant 10 or so fruit and nut trees in my new garden. Looking at vendors like Thompson and Morgan or Crocus they seem relatively pricey and I have no idea if they deliver value or not. Reviews suggest some people have had problems with their trees dying in the first few weeks (might be a vocal minority as is common for reviews) and for the same/similar variety is it worth it compared to say B&Q (or dare I say even B&M)? I’ll need delivery too.

Side query: What are your top recommendations for fruit and nut tree/varieties? I’m zone 9a, coastal northeast England.