A G150 is a nice plane (I've demo'd one) that is fast & efficient, but its way overkill for "short business trips" for 6 pax or less.
Look at a CJ2+ or CJ3...400kt+, ProLine21, single pilot capable and VERY economical to operate, compared to a G150 and especially any Challenger.
As a former AWACer myself, I can get you any route info you want on the CJ2+ if ya want.