Questions. The big question is do you have access to that kind of capital or even a portion of it? If so, why not strike out on your own if things are already looking grim? How big is your market and how well does word of mouth advertising work? Are you a local boy where a lot of people know you or a transplant to the area that doesn't really have a connection to the people? How social are you? Is the area saturated with other IT shops?
The main reason I ask is that if I were personally in your shoes based on what I know of the situation I would take $5k-$7k, register a new business, get the basics taken care of (logo, business cards, CPA, lawyer, distributor accounts), purchase a solution for taking credit card payments, keep my books in an excel spreadsheet until I needed something more robust, join the local chamber and other business groups, and start spreading the word.
If you really feel you need a store front find the cheapest, smallest thing you can work with that has the shortest lease. Ask if they have any way to provide previous records of utility costs to help estimate costs. Some will, some won't, and sometimes you can call the utility company and give them the address and they will provide it to you. Also, have enough in savings to either cover your lease or at least the first 6-12 months of rent & utilities.
Business will start to flow as long as people know you are there, that's why I asked about being social. Tell everyone, always mention it. Think of how a car salesman always seems to work what they do into a conversation. They aren't trying to sell you a car at that moment, they just want it their name and dealership to stick with you and be fresh on your mind in case you need a car or know someone. I would also work on getting your name to business clients more than residential for two reasons. First, residential clients talk to other people and spread the word for you if you treat them right so word of mouth works best for them when it comes to advertising, also asking what they do for a living/where they work goes a long way to because most people probably work somewhere that could use support services and it also makes for good small talk. Second, besides the fact that business clients tend to pay better, they are essentially made up of residential clients. Maybe the business doesn't need your services right away but what about the secretary or manager that you spoke with and dropped your card to, maybe they need it and afterwards they like your work enough to give you a shot at supporting their business.
As far as your current boss, I would tell him thanks but no thanks. Although you've been with him for a while you don't know what kind of bridges he has burned in the past with clients, which bridges he will keep open when client XYZ insists that he still support them, and how many of those clients won't roll over just because. I would offer to make him a deal to either buy his client list of customers that have been serviced in the past 3 years at a set amount per client or offer to pay him a referral fee per client/job sent for whatever term you see fit.
Hope some of this helps on your journey. Remember, always carry business cards, never be afraid to ask for help, and never be afraid to turn down a job that is above your skill level.
