You are unlikely to get insurance at any price on the three airplanes
listed, given your hours and especially for business flight in an
airplane you don't own... Check with your insurance agent...
I agree that that a Seneca is one they may cover, or an Aztec, but the
insurance will still be costly until you have 1000 hours total with 500
hours in ME... Consider the suggestion for a propilot to help you
build your hours - this is a win-win situation with lower insurance for
your boss and free time building for you...

Denny