woah... you need to turn this thought around in your head and approach it differently. It's fine that you want to get back into the single client game, so I won't talk you out of that. But you need to look at yourself differently. You have been the owner of a business that has lasted for 6 years. Do you know the failure rate of small businesses in the first year... how about the first 2 years. hint: it's more than half. So congratulations on being a tremendous success and outlasting many others who didn't make it as well as you.
Now, your future. I just left a technology services company (VAR/staffing/projects/consulting) that I was at for 8 years. For the last 18 months there I hired in people in your exact skill set. I would recommend that you go to work for a company like this over going to some company where you will be just part of the desktop support team for the next 20 years. Get with a company that is like what you are doing now only much bigger than you, and I don't mean geeksquad... Did you sell hardware at all? Did you use Ingram or other distributors? If so, look up your former competitors and go to them. You have much more leverage with a company like that. Why? You have clients - those equal clients for your new employer. You won't have that advantage by going to work at the local hospital or bank. If you know some of your competitors, take the owner to lunch. Tell him you'd like to come to work for him and hand over all your clients to him and all you want is a) a one year contract with no non-compete or b) a portion of revenue from every client that you are handing over who converts. Look at what you are doing as your exit strategy, not giving up for a normal 9-5.
If you don't know your competitors and can't get a lunch with the owner/president then get your A+ if you don't have it and polish up that resume and get an interview. Understand that your interviewer (after you get past recruiting) will probably be a manager who has never worked for himself and who wants an employee who will make him money. He is probably bonused on the amount of profit he manages. He doesn't care so much that you worked for yourself, but he might admire you on principle. However, you still have your secret weapon - your client base. During the interview, mention to him that you have all these customers and you'd like to continue to service them at whatever place you go to work, not as a side business or anything, but as customers of the business you are going to. For the hiring manager, this is possibly more clients that he can add into his bonus column if they convert. As long as you don't come across as technically ignorant, you look better than every other candidate he has interviewed.
Some things to keep in mind about working for someone else after 6 years of being on your own:
1) Your risk of unemployment just increased by a percentage equal to the ratio of your number of current clients and 1. That is, if you had 50 clients before you would have to be fired by all of them to be really fired. Now, you only have 1 client who can kick you to the curb in a snap.
2) Your way of solving technical problems is probably going to change. You have to do it the way your company says, not necessarily the way you've always liked to. Your way might take too long and that was fine when you were running the show (not really, but...). If you went a little long on an hourly repair and you felt like you shouldn't charge the customer for some of that time, you had that option. No more.
3) What you get paid per hour is going to drop by at least 50% unless you were starving yourself as a freelancer. Also, you won't see more than an average of 3-5% in income increases annually. Use your client list to get paid more when you start with the company or you will hate yourself and your job.
4) Do everything you can to move up in your new organization. Find out who the rainmakers are - the top 20% sales people who bring in the 80% of revenue to the company (pareto is right). Identify these people and make them your preferred customers. Find out their accounts and try to work them. Get in front of them and wow them. Do favors for them, pay them extra attention whenever you can interact with them, ooze the best service all over their clients. Turn these guys into your champions in the company. They are the real power in the organization. They'll start to tell your boss that you should get more money. They'll start to talk about you to the higher ups in the company. Your name will become associated with success and you will move up and make more money.
Ok, that's all I've got. Congratulations on 6 years of being on your own and good luck as you continue your career.
