Low Budget but fast PC for Gaming/Composition/Editing and general use

I want to use this computer just generally for gaming, video editing and music composition. I'm not sure the third one has to be taken into much consideration, my current laptop runs Fruity Loops really well so the computer should be generally good enough for it anyway.

https://pcpartpicker.com/list/VV6xqk is my rough draft, but tbh I don't know much about building a computer so I've not a clue what size case I'll need, or if any of this is compatible but here are the specs that I want, although I've been told by a friend that you don't actually need 16GB or so RAM to game well, so maybe prioritize the GPU so that I can run better graphics games. At least 8GB of RAM though.

I did do a bit of research on SSD's and HDD's, and I must admit that for this context, Hyrbrid drives seem quite attractive.

My budget is around £400-£500, I understand that this outline already almost goes over that so, it would be nice the have something with the same-ish performance for under £500.

Don't worry about the software or peripherals, for those I already know the cost and have accounted for.