Remington Defense version had an Aluminum lower, and yes interchangeable grips and trigger guards. Also note the non-folding adjustable stock and Remington Defense handguards. Most recent example of a Remington Defense ACR handguard being sold went for $1200usd in the past month. To rich for my blood. Lol
Civilian Remington Defense ACR's are off the table as Remington Defense has officially axed all further efforts on the ACR. Once again another great option to replace the military's AR variants dies based on the decision that the AR is just to cheap to produce and outfit an army with so it wins by default.