Help me build!

I'm ok with computers but not amazing. So here I am asking you guys for help.

I make videos for a living, promotional content, music videos etc.

I want a new build as it's been four years since my last one and although it runs fine I'd like a new one for myself and my business partner.

It needs to be able to edit 4K footage, possibly 4K RAW footage depending on what camera we buy, either way it's going to be data heavy 4K. We don't do any 3D but we do a lot a transitions which Premiere Pro does not seem to like, at least on my current build (i7 DDR3 16GB GTX970 SSDs), slows it down quite a bit.

So can you guys help me with something which will handle 4K well, preferably i7, DDR4, CUDA enabled graphics card, SSD for OS & Apps.

Like I say, I'm not the most educated or up to date on this stuff so recommendations will be greatly appreciate, PCPARTPICKER links even more so.

Budget is £1000-£1200 for build only (no peripherals)

Thanks!