But [link|http://www.usau.com/USAU.nsf/Doc/BonanzaDataSheet|this is telling]. Bonanza is over 50 years old and has probably killed more rock starts than drugs (there have been issues with the V-tail).
Mooney's cover the speed issue OK, but while the plane may have 4 seats, their useful load isn't so hot and they are PRICEY. Expect to pay $150k and up for a mid-80's plane.
The [link|http://www.airbum.com/pireps/PirepQuestairVenture.html|Questair Venture] is a nice example of what could be done today with a little thought. Its only a 2-place but it's freakin fast and still fairly roomy inside.