I think you should be open to a master tech or a solid mid level or B guy. This will broaden your search. Also don't be shy to interviewing someone with less experience that has the aptitude to learn. I have a lot of industry friends that have done very well taking the delivery boy and bringing them up to the level of a master tech!
This will really determine on how strongly you have a grasp on your business financials. What I mean by that is, you won't be able to begin to figure out compensation until you know what they are costing your business as a COG. Generally speaking my advice is to start a culture of some sort of meritocracy. Make sure that a compensation plan is based upon performance. You will have to fine tune it to make sure that a tech won't just try to milk the system so the bonus will probably have to include comebacks, overall shop goals, etc.
This is the tricky part. It sounds like you are working really hard (long hours) but you aren't "killing" it financially yet. I am going to assume you are making money but not the kind of money where you could easily pay a tech to replace you and have a lot of room to learn the other side of the business. This is where I would say make sure you are looking at what you are actually charging for your services. What is your Gross Profit % on labor, on parts, what is your Average Repair Order, how many hours are you billing per ticket, daily/weekly/monthly car count. I think if you start by implementing some positive moves on your front end you will have more a financial cushion all the while putting out ads and such to find that first hire.
As far as how we grew well I have a partner that is the "tech" and I was the front end guy. The drawback is we had to share the business 50/50 however we had each other to lean on and we had complementary skills. How I personally grew was getting education, reading (a lot), listening to podcasts and watching videos, going to conferences and in person training events, learning how to be a better business person. I would highly recommend self study as hat's where I found a lot of "power".