clandestine
AR-15 Savant
I know I'm a little late to this, but I'm going through the process of building a an AR9 now myself.
I've seen a lot of good things said about the Blitzkrieg hydraulic buffer: http://www.blitzkriegcomponents.com/ProductDetails.asp?ProductCode=RB5007
But I'm going to start with the Taccom: https://taccom3g.com/product/taccom-pcc-adjustable-buffer-system/
Both are a waste and just add unneeded complexity.