Any chance of you building the PC yourself or not something you're looking to do?
Even if you don't build a system yourself, their guides can be a good check list for one you'd buy from a supplier.
Thanks again for the help. Brief recap.: bought an off the shelf PC which appeared to do the job but then started to malfunction and have just returned it. It was a useful exercise as I now have a better idea of the spec. that is adequate.
The lad is now agitating to build one himself as this will allow him to choose a case (very important, he prefers Muji style to the usual gamer aesthetic), gains bonus points in his social circle, learn some potentially useful skills, and because it's all over YouTube. Strangely, building your own seems to be currently more expensive than buying off the shelf. I am assuming I'm going to have to finish the job/pick up the pieces when it goes wrong. Whilst I'm not clueless (see further up the thread) I'm a bit nervous when playing with £600+ of parts without a helpdesk to phone. The lad's answer to all this is 'just look on YouTube'. He's probably right but I need reassurance...
By all means ask any questions you might have here but also i'll link you back to this site:https://uk.pcpartpicker.com/
They have suggested build guides that you can trust to contain compatible parts. Also a useful forum section.
Your lad is actually quite right about 'just watch YouTube' there will be a world of useful tutorials on there or you can google specific questions.
Ultimately just be very careful and take it nice and slow on your first build. Don't be afraid to check, double check, watch 2-3 different tutorial guides and you'll be fine. A poster above mentioned the CPU/Motherboard pins being a potential site where you can make a mistake. So depending which CPU/Motherboard pair you go for I would definitely check an up to date guide for your exact cpu+socket type as they do vary.
In terms of it being more expensive to build your own I think this is usually a case of not comparing apples for apples. The pre-built options might have a relatively cheap PSU/case/motherboard/RAM/SSD but will headline the GPU+CPU for example. So I would have thought you can be competitive on price and have a fun, learning project at the same time.