If it were me, I'd go with either Armalite's AR-10 or DPMS' LR-308. Both have a broader presence.
I am not saying the RRA is a bad rifle, but there just aren't a lot of them out there, and if there is anything proprietary to it, you may run into problems.
Do you know if the RRA is on the Armalite or the DPMS pattern-- or a proprietary one? I haven't really looked into those.
I do know that I am very pleased with my DPMS LR-308. It, the FAR-308, the JP Precision Rifle, the SR-25, and the Remington R-25 (which IS a DPMS) are on the same pattern. Armalite, however, has a deep presence in terms of aftermarket support as well.
Just something to think about.
-- John