I have a DPMS in 243 Win and my brother has a DPMS / JP hybrid in 260 Rem. They are the cats ass. They can get kinda heavy, but if you're man enough and you want a 'kill anything' gun, that is the way to go.
I also have an Adams Arms / Magpul / Spikes Tactical hybrid in 556 that I like a lot.
My advice:
1. Get a mid-length piston-driven gun. It limits your options, but is worth it, especially if you think you'll ever shoot it suppressed.
2. Get a fast-twist barrel - like 1-7 or 1-8. You'll be able to shoot heavier bullets (>60gr) with it while lighter bullets should still shoot well.
3. Piece it together. You'll get all the stuff you want the first time instead of replacing things over time like I did with my 243. Typically the best upgrade is the trigger. While they're getting better, most factory triggers still suck. You won't be sorry with a Geissele or Jewel 2- stage.
