Welcome to the forums! [img]smile.gif[/img]
I just recently purchased a 9C1, after having been a fan of the B-body cars for as long as I can remember. The 9C1 relpaced a 1991 Buick Roadmaster and 89 Caprice Sedan as my daily drivers. My 9C1 was an unmarked State Trooper car, but without the spotlight that many of the 9C1's you'll find for sale have, I figure it was a detective car. I got the car with 190,000 miles on it, and like you said, despite the high mileage, the car feels and drives like it just rolled off the lot. The car is a dream as a daily driver, in fact, I'd describe it downright fun.
When buying a 9C1, I'd reccomend looking for a state vehicle. When I was looking around, it seemed like they were the best maintained despite whatever mileage they had on them. I would definately stay away from county or city vehicles, as they're usually trashed and not as well maintained.
In my experience with my 89 Caprice and 91 Roadmaster, these cars have been incredibly reliable. When I picked up my 9C1, it needed a new EGR valve and Solenoid, but other than that, was totally solid. The water pump seems to be an item that is a bit flaky on the LT1, from what I read. Knock on wood, hopefully mine still has a good bit of life in it! [img]smile.gif[/img] You mentioned that you'd be doing a lot of suburban driving, and the only issue I've found with that is that in a lot of stop-and-go traffic, the car tends to heat up quick, but I'm looking to drop in a 160* Thermostat and PCM reprogram to help with that, turning on the AC (Which subsequently turns on one of the electric fans mounted behind the radiator) helps to curb that until then.
I'd wholly reccomend you getting a 9C1, granted you can find one that you feel good about. I was lucky to find such a clean, well-driving vehicle despite the mileage on it. You won't regret it.