hey man, you should seriously consider starting with a stock weapon. Learn to shoot with the iron sights, you might find out that you like them better. Once you get some experience behind the AR you will have a better idea of what you want to do with it. If you start stock you can always add optics, etc. later once you have a better idea of what you want, but if you buy all of the extra crap now you can't go back.
There are a lot of other expenses involved that you are forgetting about. Magazines and ammunition brother! A 2200 dollar rifle is just an expensive club without mags and ammo. Get a stock carbine with a removable carry handle to start with and go from there. Personally I prefer the Colt 6920, bushmaster is good too. I here good things about other manufacturers but have no experience with them. Spend a grand on a stock rifle, spend a grand on magazines and ammo, and if that other 1,000 dollars you have is really burning a hole in your pocket go get some formal training. Other then that, hang onto it until you have a better idea of what you want.
I personally feel that you are severely cheating yourself if you start out with anything but iron sights. For one, you won't be able to appreciate the good things about the various optics out there if you don't. A stock 6920 is a pretty fucking bad-ass weapon. Personally I feel its got just as much of a "cool" factor as a rifle with all the shit on it. Accessorize as you go, as you discover your actual needs, as you learn. I used to have all kinds of stuff for my ARs and now prefer a stock 6920 to anything else, except maybe a good tac-light (surefire or even stream-light's M-6X). I am thinking about getting a compact acog as a toy, just like my EOtech is a toy. My go to gun, the one that I enjoy shooting the most, is the stock AR, the way it was meant to be.