I'm a big fan of the AR-10

Look up AR-10 rather than AR-15 for the .308/7.62mm version.

The purists will state that only Armalite and KAC depending on who you talk to are true AR10s. But generically all of the .308/7.62 AR rifles are referred to as AR10s.
You have a number of options. But your 2K price cap limits those.
Questar is a good place to look. Wolverine is also another good place to check.
For price/performance the DPMS LR-308 is hard to beat. But... you'll need to put in a match trigger. The stock one blows. Unfortunately you missed the one at Questar by a couple months. They are sold out right now.
The Remington R-25 is a camo DPMS with a lighter barrel. It's your cheapest overall. That being said if you can find the DPMS LR-308 it's probably worth it to get that one instead.
Rock River Arms LAR-8. I know Questar sells them. When I was buying mine, this wasn't an option. There was also a very bad history associated with the design of this rifle (FAL mags in AR10 don't work too well). Bushmaster bought the design, couldn't get it to work and RRA took the project back. I believe they have sorted out the issues now though (It took them ages to get this working). Do your research on this one before buying.
The RRA rifle has a 26" barrel instead of the 24" of the DPMS. Which might work well for you. Both are 1:10 twist . The RRA comes with their two stage match trigger, which is the same one I put in my DPMS (Will cost just under $200 to buy and then you have to install it). If you wanted a Kel-Tec RFB later on, your RRA mags should be compatible (use metric ones).
Armalite is pretty much impossible to get now unless you get one second hand. Their target models are comparable to DPMS but at 3K. Generally I'd dismiss the Armalite target model due to the cost and magazine. Although the Canadian military model rocks. Also there are some very nice put together rifles out there which I think are nicer than the target model. The Armalite rifles also use modified M14 mags.
Keep in mind most of the parts on these rifles aren't interchangeable like the AR-15. Other than triggers, pistol grips and stocks they have their own uppers/lowers and mags. Some use the same mags such as the SR-25 (KAC), the DPMS and a few others. These mags are based off the original AR-10 mags and personally I think they're the best ones. RRA uses FAL mags, Armalite uses their own modified M14 mags.
DPMS LR-308 24" 1:10 twist barrel. It's stock except for the RRA NM trigger.