Re: What Type of Chevelle Should I Search For.
You've posed a very open-ended question. Beyond your budget your first issue is which model/body style. It sounds like you are focused on the later body styles of the 69 and 70 models, maybe even 71-72. Those tend to be the favorites.
After that comes how much horsepower do you want. You said that horsepower and speed are not that important to you so, a car with a 350 engine vs. a 396 or 454 would likely suit you fine. (454s can get expensive).
Then do you want stock (generally factory set up) or restomod(ish). Personally, I like stock, but that is a personal choice. And do you care if it is matching #s (orig engine, trans, etc.)? Matching #s cars are a bit to a lot more valuable and cost more.
Then the bells and whistles (options) you want on the car. You mentioned A/C, for instance. You may or may not find the car with the exact options you want, so you might try to be a bit flexible on that.
Finally consider condition- have someone check it out for you, put it on lift and see what the undercarriage looks like. You sure don't want a rust bucket, no matter how pretty it may look on the top side. Make sure the body is not filled with bondo. And have the person checking it out look over the engine and trans, drive it, do a compression test etc. Make sure you are getting at least a decent engine since rebuilding the engine is expensive.
Overall, I think it is worth it to spend a bit more and get a car in better condition, than to spend less and get a project, especially since you are not an accomplished mechanic or body guy.
Since you know you are not a gearhead, you'll need a good classic car mechanic, like you said. You might go find one of those before you buy so that you have someone that can inspect the car for you. And they can tell you more about things to look for, good and bad. Find a shop that specializes in old cars, not a shop that works on old cars too. Such shops are a bit harder to find but they are around. I have a shop like that I have used for years. It is just 2 guys but they are invaluable, and better than anyone else I've come across. You just have to search a bit more. I do a little work, but I'm much better and writing checks for pros to do the work and then driving the car to car shows etc. It is way more fun when the car runs right.
As for looking, you might go into your local Gateway Classic cars showroom. There is one in Houston and they have several Chevelles for sale. I just looked and they just sold one for right at $31K that looks like it might have fit you needs well. But, they have other Chevelles and LOTS of other cars too and you might find something else you like just as well. It is sort of like an indoor car show.
My Chevelle turns 50 in May, and I've had it for 45 years. Chevelles are a blast and I'm sure you'll enjoy owning one, or any other classic car you might get.