Will second vrumor.
Your best bet, I think, is to look at the employment ads and see if any businesses are looking for "PC builders".
Overall, the approach I would recommend is that you prepare a resume listing your education, experience, and skills with respect to PC building.
Look for small businesses that build custom PCs or companies that provide IT support to large groups of people.
The requirement is and the effort you must make is to convince a potential employer that you can do the job.