The idea is great! And you are right, there's so many people that think they are a maxi but in reality they're just playing to be one. I could suggest you to start playing with the finishes you have in your pond already. For example, talk with your employer and ask them about your plan, if they really care about you, your expertise and value you're bringing to the company should be no issue changing your contract and have you consulting them first.

I know it sounds crazy, but asking is free and if you do not ask you'll never know. When you are comfortable with your existing clients, you should explore open waters and go fishing out there!