It's only a 16" barrel but it has everything you want on your list. It's a bit heavier than some but it's very accurate and easy to keep in the "A" at 200 meters (with prone aimed shots for me and less reliably offhand).
I have shorter arms than most so I like to use a grip pretty far back on the rail, I hold it on the top more than holding the grip itself. I'm working on moving it forward.
he's the list
* Lewis Machine and Tool MRP QCB 16" non compliant Defender model AR
* Rock River Arms 2 stage Match trigger polished and greased
* AimPoint Comp M4 red dot
* AimPoint Front and Rear Flip lens caps
* Troy Industries HK style front flip sight
* Troy Industries M4 Rear flip sight
* Troy Industries Pro Grade Sling Adapter with swivel clips
* Specter Viper 1 point tactical sling
* Magpull Forward battery assist device
* Tango Down forward Assist QD grip
* Viking Tactical Light mount bracket
* Phoenix 210 lumen e series flashlight