Clearances is the single biggest issue facing the bigger twin tower coolers. My Raijintek Nemesis won't fit on my Msi mpower z77 simply due to the heatpipes coming into contact with the VRM's heatsinks surrounding the socket. Which no one, including myself, predicted.
It'll be no different on an x99 board with the R1. There's low profile ram and lower profile ram. SR-71's Snipers aren't the lowest of the low profile, they do still have the sniper gun on the top of the spreader. There's ram with removable sinks, which realistically doesn't hurt performance. It's going to be trial and error at least unless you find someone with the same x99, running a particular kind of ram, with an R1 cooler. With tolerances as tight as they are, and the sheer amount of variables, its realistically impossible to accurately say yes it fits or no it won't.