For that small of a shot, you could hide it from sight and still tell people it's fuel only! I've heard of a few sled pullers that had hidden nitrous systems!
Driving a 12v and a 6.7 don't let all the talk of a large quick spooling single sway you. The old mechanical trucks need compounds to have the spool and power a big single CR rail no questions asked. Go with the twins you have all the supporting mods and you'll wonder why the hell you waited so long! The egt control and drivability of compounds will keep the motor cooler and make it last longer and be far more versatile than an undersized single and nitrous.