Choosing an AR 10 upper

If you had to find an upper to match an .308 Armalite Eagle lower what would you pick and why? Run the gammit, as far as the bestest mofo you could find (even if you can't afford it). . . to the most economical/quality lower that would be practical for a guy who didn't want to break the bank. Just enlighten me, and explain why you would choose what you chose, and what criteria should be taken into consideration when choosing the particular components of the upper you like. I would assume its better to keep things uniform and acquire an Armalite upper to match the lower, for resale value if nothing else. From what I read at Gunblast.com about the Armalite Eagles, I suspect the stainless barrel is the main difference in this entry level AR10, when it is purchased as a complete weapon; still, I haven't a clue, which is why i'm hear asking you. This is not a subject I have vested a great deal of research into, so I am looking to obtain some advice from those who are familiar with the .308 AR platform. Any do's and dont's, shoulda wouldas, or mighta couldas will be well received; i'm open to the constructive criticism that comes with being schooled. Essentially this will end up being used for self defense in a SHTF situation; it may get used to plink every now and then, but there is cheaper ammo out there for that sort of stuff. Not that I could ever see a reason why I would need to, but should I ever have a need to go snipe hunting I have bolt actions that would work better for that scenario, so I'm not trying to build a tack driver, just something that will ring the 10 x 10 steel plate at 100 - 200 yds.