Downhill/Cross Country probably doesn't mean black DH routes- i.e. maybe full on DH gear isn't required
He said he wants to go at great speeds - ergo the Full Face helmet reply.
Also a full face is a good idea for red runs too if you plan on pinning it

What about a skate style helmet (**** pot) or a met parachute? Really doesnt sound like you need a full face helmet.
As burned said above - you need a p!ss pot in my opinion.