It all comes down to what type of riding you do, I ot the ROACHes because I have some VICIOUS pedals. I am in the same boat for the elbow pads, never really needed them, all of my boo-boo's are on my palms or leg/knee/shin. If I where you Id get the roach leg armor, and then get 661 veggie wraps, protective, but not overly protective like the roach, but its up to you.
As for your bro, I am getting a full face aswell, I am not a downhiller, but a freeride with an XC bike, the drops and things I do arent to hellacious, but I always have that fear of smaking my jaw onto concrete, Id rather look goofy witha a helmet thatn goofy with facial disfigurment for the rest of my life.
-Jacob