Hi Squib , I would suggest a custom Pc builder , there are quite a few online , examples are Scan , PC specialist , Computerplanet and many others . Most will have prebuilt stock , but can build to your specs . I can personally vouch for Scan.co.uk , having bought my Pc from them . They have a system that would suit you very well , the V15 system , costs around the £ 450 mark .
OnePlus 5T review: Hands-on