Easy Hoss. Just breathe........
The cheapest solution is to have a 4 rail gas block installed. You can then mount the laser under the barrel. Otherwise, you need a rigid, full float type of handguard to mount a sighting system or it's worthless. The handguards that are not rigid and floated are fine for lights, but that's it.
Daniel Defense is very good, but not your only option. You could get a FIRSH handguard by Oly or use a free float tube by JP and then add a picatinny rail bolt on.
V Tac by JP (I've made most links hot, so click 'em!)
That will only set you back around $150.
Don't get hung up on the combat gear. JP is good enough for 3 gun and we bounce rifles off stuff all the time!
The JARD trigger is another drop in trigger type. The other options I listed will likely work, so don't sweat it. Most good trigger systems run $140-$200. A standard trigger group is just that....a standard single stage trigger than comes on all AR's. These guns are modular and many of the manufacturers use teh exact same parts from the exact same companies! Wilson (NOT Wilson combat) makes barrels for several main line brands...... You can get the standard trigger group down to 3.5lbs just by treaking the springs, but you may have some creep.
The DPMS guns are excellent choices, HOWEVER, for $1100 you can have a Gator upper with carbon fiber OR DPMS aluminum tube (that will accept adaptors I believe), a chromes bolt and carrier, a muzzle brake (should you wish), match barrel and JP adjustable gas block (you can adjust the gas pressure to match your loads). All that with a guranteed .5 MOA. No shelf rifle comes close to that for the price....period. You don't need a 1.15 barrel. I can watch the strikes in my 20" gun and it's .960 I believe (too lazy to mic it) 1:9 twist handles 70gr bullets. Unless you really want to shoot heavier out of .223, you don't always need 1:8 or 1:7. If you want 1:7, go White Oak. They make their living shooting 600 yards at Camp Perry. Don;t get hung up on barrel length. Longer barrels are no more accurate and with good bullets you can fragment much farther than ball ammo.
Even if you choose to go DPMS, just get the upper and mate it to a RRA lower.
IT WON'T MAKE IT LESS EFFECTIVE AND WILL SAVE YOU MONEY.
Really.....I'm just trying to clear up some things I've learned over several thousand dollars and competition.
Now on to the AR10........that's not a bad price at all.
What else you want to know?