I was issued the EoTech, if they are issuing ELCAN's or RCO's go with that so you aren't spending your own money. I did love the EoTech on it, very fast to acquire and never shifted the zero.
I can't say either way about the dry lube as I never tried it out. If you get another range session prior to deploying give it a shot, just make sure it isn't already dripping with CLP. I know guys who love dry lubes and those who hate them, however I know the Hoppes worked so I stuck with it, and a daily cleaning took care of any sand it attracted.