I purchased this a week or two ago and have decided to go shorter
SLR 9.7" SLR ION Ultra Lite with 5.56 barrel nut for $155 shipped. It retails for $230 from SLR and is perfect for 10.5 inch builds.
I mounted the barrel nut and did a test fit, but none of the fasteners have ever been used or opened. Oh, and it's Gen 4, which is the latest model.
Barrel = sold
Rail is still up for grabs