I really enjoy both the PC system and my Brittain Accu-Trak. I fly the heading bug almost all the time. The previous owner fixed it up, added the heading bug and interfaced it with the 430 to fly approaches, leaving me to work the radio and control altitude. It's really nice. Although I frequently forget to press the PC disconnect button, it's pretty easy to overpower, and the extra resistance makes me unlikely to overbank in the pattern.
Expect your flight times to decrease 1/3 to 1/2 compared to your 172. Navmonster is quoting 1 hr 17 min BFM-AUO for my C-model, so football games will be closer. With any luck, I'll make it down for a game this fall [2 hr 41 min]. Yes, I'm an alum, Engineering 1986. Been flying the Mooney since 2007, which I bought at 62 hours.
Concentrate on a good airframe, solid maintenance history in the logs, and a modern panel. This means the standard 6-pack [top row, Airspeed, AI, Altimeter; bottom row, TC, DG, VSI]. Some of the older planes have these scattered almost randomly around the panel, mixed in with VOR's, ADF, etc. Look through the gallery here and you can probably find some, especially if Dave Morris has his A-model posted.