A King Air type rating is an excellent type rating to have because there are so many of them out there. That also makes it a dime a dozen type rating to have.
The most desirable type ratings might be ones which are based in an area in which you want to live/base, or a specific company that you desire to work for, though paying for one on your own dime can get expensive - even if using assistance.
There is a mature thread on the forum in the Fractional section for Executive AirShare (EAS). Check them out. A new outfit called Wheels Up seems to be in the process of interviewing too.
Do a search on the forum, target the Fractional subforum, and even search for King Air in the title and you'll come up with good reading to answer most of your questions.