Bottom of the barrel stuff sub 48" nowadays, can't really say one TV is going to be better than another. Best thing to do is spend less. Have a hard time recommending Samsung because you don't know the kind of panel that will come on the TV in Europe.
My advice to your friend would be
1. Smaller TVs are all low end models now, if he wants better value for money shop instead at 48-55".
2. Smaller TVs are almost pointless to enjoy 4k content, to get extra detail you need to view very close.
3. Because smaller TVs are all low spec, no TV can display HDR properly which is one of the key reasons to buy a new TV nowadays, really TVs that are true HDR models start at 49" and higher and cost around £1000. The Hisense 50" U7Q gets half way there and costs £600. At 55" the Hisense U8Q also is a good HDR TV costing £800. Unfortunately lower sizes and lower budgets makes HDR a no-go.
If he's still set on buying small TV and doesn't want to save up for a higher tier, larger model consider just buying as cheap as possible. A £300 TV is not going to be better than a £600 one at 43". Black Friday should have some deals on models around the 300-350 mark.