I got a company called pcspecialist to build me a desktop. Id read a lot of really good reviews about them. I'm not that techy at all but did quite a bit of reading about what spec I needed for size of memory, processor, etc.
They have a chat forum as well where lots of more techy people will advise.
The ones where the display is the hard drive look cool but I was concerned that down the line if I wanted to add more memory or if an individual componment failed it would be a lot harder to open it up and change stuff/might not be enough space to change stuff.