I heard about a fun little website the other day by the name of Pimp My Gun. It is a little image editor that lets you create your own little killing creations. You could of course make something ridiculous, but I have had fun making weapons that are at least somewhat plausible.
Check it out.
CTAR-21 with quick detach suppressor, Eotech holo sight and foregrip. Yes please.
You can't tell me that this isn't bad ass, I would load the 203 with the M576 anti-personnel round, loaded with 20 pellets of #4 buckshot. That will really clear a room.
Can't go wrong with a little modified Mossberg 500