www.1fast400.com recently started carrying Maca Root powder. I plan on buying that along with the Nitrous that I already take. I've never taken Damiana though.
www.bulknutrition.com has bulk arginine for pretty cheap. Also add some lecithin and zinc to the stack (got mine at CVS). That's what I'm doing right now. 6-9g of arginine, 60mg of zinc, and about 10g of lecithin per day. My loads are getting HUGE!!
Oh yeah...and the ROP. It cured my acne problem too.