Hmm, you brought up some good questions. I Like your idea of having the longer outer barrel with a shorter rail system, but then having the silencer on the end but shorter. Also, I plan on moving more with a 2 man team, sniper/spotter sort of.
Also with the Hop-up, How does this look? Im sorta new to hop-up types so im not really sure.
http://airsoft-club.com/shop/interna...eg-50-hardness