I’ve used ZZ Computer for something like 20 years. They have built 3 or 4 computers for me, all of which have performed well. Most recently they repaired a computer that had gone haywire in a transition from XP to Win 7 64 bit.
In my experience, they have always been competent and honest, and have priced their work fairly. Ron has even warned me of problems before they appeared, such as a bad match of a case with a microprocessor. (He was right; the unit overheated and the whole thing had to be moved to another box.)