You might want to consider the Rock River Arms set-up. When they first came on the scene I bought one of their 1X8 stainless barrels and I've had good results with it.
I tend to treat it rather poorly, but it has held up. For instance, I baby my Krieger and feed it only my best reloads. I tend to shoot my RRA. Not only do I shoot it, I also feed it a lot of crap.
You can squeeze "decent" accuracy out of an AR with a 1X9 non-floated barrel (if you don't sling-up tightly) and $5 a box ammo.
If you want something great, then free float a good barrel and feed it great ammo.
If you don't want to swap out barrels, you might want to chek out the RRA DCM complete upper.
Like I said, I get good results from my RRA barrel and blasting ammo. They're not as great as they could be, but they're good.