What about a calico i have no ideal about power, but they are not that big, an they hold 100 shots, an they look wicked. go with style calico

http://www.dwsuk.co.uk/New_site/Other/calico.htm
http://members.tripod.com/~Slippery_Jim/Subs/Calico_M-950.htm

That thing looks more like a submachine gun then a pistol... But I've got to agree, it looks really wicked.

Dude forget about what I said on SMG's not being cool enough, dual anything looks crazy. Think about it, your mac-11's with mercury filled ammunation.