Not all dealers but MANY of the dealers around here don't know a lot about ARs and accessories. Mainly because they don't USE the things. Selling ARs and actually using them are two very different things. Selling alone does not give you the experience.
Okay, now that I'm done with my semi rant...
You really need to decide what you primarily want to do with the rifle. My RRA Varminter is AWESOME in the accuracy department, but it's so damn heavy I'd never consider carrying it for lengthy periods in the field.
A couple of my carbines are setup for CQB. They have rail fore-ends, vertical grips, lights, collapsible stocks, Aimpoints, etc. They are very easy to handle and allow me to make "practical" hits up to 200 yards. By practical I mean center of mass, which aren't necessarily precision hits.
That's why I agreed with P806. With a 20" government profile you get a longer sight radius and a lighter weight barrel than an HBAR. The only thing I might recommend differently is an A3 (flat top) upper. If you know you're going to want some kind of optic, whether a traditional sytle magnified scope or a dot sight, get teh A3 because it will give you more mounting options later. And, if you DO get the A3, I vote to skip the removable carry handle and put the money into a good BUIS (Back Up Iron Sight).
The thing that will drive you crazy is all the options you have. You can buy one rifle and forever modified it. Picking the right stock alone can drive a guy nuts.
Where are you located in the state? I'm up in Braselton. Best thing to do is try different things, if you can, before you buy. If you can't, a 20" government profile is NOT a bad way to start. I might suggest an A1 length stock for it. Would also advise to get the A3 for more options down the road.