I do tech support and will be starting my business soon. I have worked for large corporations as well as a local tech support provider for businesses and individuals.
When you think about tech support, you might consider how you would think about finding a mechanic. Ask around, ask your friends where they go. I take it you have limited technical knowledge, just like I have limited mechanical knowledge of my automobile. So below I have listed the 4 best attributes from your list you should consider.
When I take my car in for service, I am looking for someone who is knowledgeable, friendly, honest, can explain to me in plain english what is wrong with my car, and have, of course, a lot of experience.
Your tech support experience should make you feel better about the money you are having to spend. They should put you at ease about your system, and be able to explain exactly what is wrong with it. You should not feel like you are "bugging" them-
I also would try to educate yourself a little bit about what makes a computer work well and efficiently, as well as antivirus, antispyware, etc. You will save yourself a lot of headache, be able to do preventative maintenance on your system, and when it does finally crash, at least you may be able to understand a little about what is going on.
When I go to my mechanic to get my car fixed, I can understand what he is talking about. I also do preventive maintenance myself- changing the oil, etc.
4 best attributes to look for out or your list:
the techs are friendly
the techs are knowlegable
the techs have loads of experience
the techs speak in an easy to understand language
Also, one last thing- the most important, MOST IMPORTANT thing to consider as you start to learn about computers and getting them repaired- BACK UP YOUR DATA!!!
I have seen people lose pictures, financial data, important files, etc. Once they are gone, they cannot be recovered.