dave
As you get bigger aircraft you talk old which makes me suspect that the budget is not high ?
This is often the problem with non aviation company directors they look at something and all great until you talk acquisition and running costs. Bigger and old means high running and maintenance costs
You mention that a stand up cabin is not needed so if the budget is low as I suspect and they could keep to 7 PAX with light luggage a Citation 5 Ultra has the range, low purchase and running costs and short field capability
But that is bottom of the pile if they just want a workhorse at minimum cost and can knock off one PAX
Lear 45 mentioned is horrendously expensive to operate
Pace