Single pilot, four passengers, up to 800nm trips, and no headsets for absolutely no more than $250k. The CEO sounds like he has filet taste and a ground chuck budget...not entirely uncommon.

He needs to have his expectations adjusted back to reality...again, not entirely uncommon. Even if he can afford the plane at $200-250k, can he afford to operate it? After all, if he doesn't operationally budget for anything other than fuel expense he's going to have a rude awakening when it needs maintenance or when annual time rolls around.

Our company operates a Cirrus SR22 in addition to a jet...and while its often used as a short range <150nm shuttle it also sees 500-600nm trips pretty regularly. Good plane for one pilot and one passenger over that length trip, but one pilot and two pax can start squeezing range...especially if the folks are bigger than 180lb average or there is much in the way of baggage.

Ours is a 2007 G2 that is loaded with options...AC, oxygen, TKS, everything but the turbo. Our full-fuel payload is about 440lbs, but an airplane without TKS would send that number up quite a bit. From an efficiency/operating cost standpoint, its hard to beat 165kts @ 13gph (flown lean of peak) in a SE piston.

Within the aforementioned budget, a 2002-2005 SR22 should be considered (assuming 4 pax + pilot isn't a necessity), otherwise for six seat capability A36, B58, Seneca II/III or late-model Aztec, or Cessna 310R or 340. But everything has tradeoffs...payload, range, operating cost, etc etc.

Good luck!