Similar Circumstance
I have a similar circumstance in that I have just secured a part-time Part 91 King Air 200 gig. The pay flying 6 days a month is better than most Regional airlines first year pay. The plane is based within 30 minutes of my house. I will be home 20-25 days a month, and can still keep my Part 135 job (also part-time). Down side is that I will not be building PIC turbine time quickly. The job currently requires about 6 to 12 hours per month of flying, to go to about 20 hours per month within a few months. At 20 hours per month, it will take me 4 years to get to 1000 hours turbine PIC.
That being said, I have 2 questions. First, is there any reason for me to ever go to a Regional, assuming the job remains the same? Second, will 1000 hours PIC in a King Air get me a shot at Major? (I will have over 4000 hours by then, and probably over 5000)