..for just a lot of data on AR's.. go to ar15.com .... it's a good site... lots of good stuff there. I would recommend you going with at least a 20" barrel, free floated handguard, etc.. I think the Jewell trigger is considered one of the best. The bull barrels are nice, but they sure add a lot of weight to the rifle... if you are intending to shoot really long range, then go with a fast twist barrel, 1-7 or so, to enable you to shoot the long bullets...

"Progress, far from consisting in change, depends on retentiveness..those who cannot remember the past are condemned to repeat it." Santayana