No idea what the third one is.
Aerostars certainly look like sex personified don't they? When everything is working they are great, if serious, fun to fly too but keeping everything working is VERY money intensive. Is that an unpressurised 600 or a 602P with the Machen mods? The two I flew started life as 602Ps and then were turned into 680/700Ps via the Machen modifications. The difference between 680 and 700P is the props.