Tim,
Any particular things you're looking for? What's your budget?
I guess on the "any particular things" I mean not only things that you'd like to see installed in the panel already (whether it's generic like "IFR GPS" or specific like "Garmin 430W"), but also if there are any particular models or mods that you're interested in, since many of them are no longer available.
For example:
1) What model of Twinkie? The "A" models ('64-'66) have only two side windows. The "B" models ('67-'68) add a third side window. The "C" model has a more modern switch style and moves the engine switches to the left wall of the airplane from the bottom of the panel. The PA-39 AKA "C-R" ('70-'72) changes to counter-rotating engines.
2) Do you want tip tanks? Oxygen? Turbos?
3) Are you looking for any or all of the Miller mods? (200hp engines+dorsal fin/wet wing aux tanks/long nose+baggage/long nacelles+baggage)
4) Do you want the Robertson STOL kit? (Adds a larger dorsal than the Miller engine mod, reduces Vmc to 75mph and Vyse to 95mph, adds stall fences and changes ailerons to flaperons)
Out of all the above things, what you get is what you get - None of it can be changed/retrofitted any longer except the counter-rotating right engine.
5) Additional airframe mods you could add later if you wanted: Knots2U speed mods (gear lobes, gap seals, wing root fairings and fillets, etc.), speed brakes, one-piece windscreen, etc.
I've been watching the Twinkie market for a long time... Narrow it down a little more, and I'd love to help you shop. But I want a ride.
I would ask on the Delphi Comanche forum, but if you can get Bob Weber of Webco Aircraft in Newton, KS, I think he's probably one of the best-respected Comanche specialists anywhere in the country.