If you want an actual jet at low cost you can get an older citation and then there is a modification they do in braketville tx that pretty much zero's it out. All you have to do is buy they jet then send it to them. For about 1.2mil they will add new baggage compartments. New engines. Pull the wings and completely redo them. New glass cockpit ect. So if you see an old citation laying around just take the price of it and add 1.2mil to it and that's what you could basically have price wise for a new jet. Operating cost would be nice and low as well as the value of the aircraft shoots up.

As far as what you're wanting you should list some more details. How many people would you like to carry, how far would you like to go, how much baggage ect and also how tall you are.

I fly a Merlin IIIB and it will fly faster further and more efficiently than a Kingair. You can put 9 people plus baggage on it. You don't need a type rating to fly that one because it's at 12500lbs. Now you can put over 14k on it illegally because the only difference between the 12.5k and bigger one is the brake pads. However as stated it's illegal so don't do it It has 2k horsepower is extremely quiet on the inside and burns around 600lbs an hour. My boss paid 699k for his and it cost around $750 an hour to operate.

Or you could go with a Cheyenne with some nice PT-6 engines or a jet-prop moves nice and fast with low operating cost.