I always thought you were not supposed to recommend products but the FE told me recently it was ok so I done a bit of work to help you.
Firstly the way to go is custom built , the "high street shop" have inferior componants to what custom builds use because the shop buys cheap for maximum profit. The customer services are a mine field , they work on what mood the person is in that you are talking to.
2 years ago I bought a rig from pc specialists , the link below shows a rig I have pretended to build just so you can see how the site works. Have a play around with it just to get an idea on how the builder process works , one thing I would recommend is ANY ssd not an ordinary one or a hybrid. At the end of the build the system checks for mismatch or overkill , say too big a power supply.
click here playing around on the page I opened for you go back to the home page and start again if you want.
FOOTNOTE... pc specialists use special packaging around components for transit , remove it carefully and depending on your components a fan cable may be left unplugged to stop it snagging , it will plug in on bottom edge of motherboard. If you don't notice unplugged wires don't panic , an extra screen appears during boot up , if it does you can turn pc off on a button on bottom right.
A lot for you to read but I hope it helps.