Hey there DrPappy...
A few thoughts for you to consider..... #1.. what is your budget? That certainly is a big factor. #2. Like you, I trained in a 172. Bought my plane actually a month before I got my ticket because I had been looking and looking and came across a great deal. I bought a 1957 Beech Bonanza and couldn't be happier. Fits my mission, flys 160KTS TAS, on 13 Gal and hour has a useful load of 1050lbs of fuel and people. So, with two average adults in front and two average teenagers in back and 40 lbs of baggage, you can put on enough fuel for 3.5 of flight time with a 30 min plus reserve. It was a very easy transition (25 hours of duel with a CFI - a requirement of my insurance) and I have flown it now 150 more hours and have zero regrets. Best part is I paid $60K for it. Hope it helps