I'm actually looking to get the same car, but
For high school I had a 1969 camaro ss "clone" 4 speed. I don't want to sugar coat my answer, and will say I would not have changed my choice at all, but it's no picnic using these cars as a daily driver. The positives were it was my first car, it gets attention every where you go, and it will never lose it's value. Some cons I ran into are it's not like a normal car you can't just jump in, and go like a fuel injected car. The one huge problem I ran into is that the car would constantly overheat & die. With mine I would constantly have to rev it to keep it running, and when ever I parked I would have to wait 45-60 mins till it cooled. Also the 8mpg was no joke, and killed the wallet. Also another thing I ran into was that I LOVE my car, and something I ran into was the inability to sell the car even when I needed to. I have listed the car so many times, but just cant bring myself to sell. I've told myself now that if I can get a chevelle I will, but it's hard to go back to a normal car after having one so be careful of that.
Final suggestion: I would say get one, if you are willing to sacrifice the luxuries of a normal car.
As far as a clone vs normal. With a clone your going to save money, but your car will never really go up in value. If you can for your money get a real one I would, but my suggestions would be get a clone, but try your best to get one with as many original parts as possible. Meaning get one with correct color paint, and ss parts as possible ie dash. Also don't get one with a super nice paint job, as that drives the buying price up, and also you don't have to worry about chips. Being an auto vs manual I love my 4 speed in my camaro, but like autos in chevelles so that's going to be a personal choice. I will say a manual adds value to the car. Insurance is super reasonable I think I paid 110 /month maybe less can't remember, buts that's in texas. Also you say your high end price is 16k, try to get one for 12-13 because your going to need that extra when things go wrong. My engine had a rod go thru the block, and has sat in my garage for 2yrs cause I don't have the money to fix it.