How many seats do you need?
How much range do you want?
How fast do you want it to go?
Do you want VFR only or will you require an IFR machine?
Are you happy to operate from prepared runways or do you want to operate from small strips too?
You have to answer the above before you go any further. When you've done that:
Airframe hours / cycles aren't that much of a problem - Engine hours are. The fewer, the better (unless you're getting an airframe with a tired out engine and you're getting it cheap enough to make it worthwhile replacing the engine).
Your budget, plus your answers to the above, are your defining factors (obviously newer is, more often than not, better than old).