Sounds like you want a Marlin Camp Carbine.An Accurate 45 ACP Carbine that takes 1911 Magazines and also has a special Hi Cap Drum Magazine that can hold 100s of Rounds and not jam
Lets not forget it also needs to be able to mounts Lasers, Grenade Launchers, and be customizable and easy to take down and clean.
It fits the first 2 criteria, but you're on your own for the Hi Cap Drum Magazine.
Lasers and launchers are up to you too, but I found one on Gunbroker that's already suppressed:
http://www.gunbroker.com/Auction/ViewIt ... =160203999" onclick="window.open(this.href);return false;
Let us know how your project turns out.
