its kind of redundant to have dual cutouts with true duals... you're already going with an exhaust system that is probably the least restrictive setup you could go with... to have cutouts in front of that is only going to net you minor, if any, gains in horsepower and it will probably decrease your torque numbers... and if you want to hear what a Rumbler exhaust sounds like, come on up to ATX and I'll let you listen to the Rumbler setup w/Moroso mufflers that are on my pewter car... its a big cam, but you'll get the idea.
just my $.02, but if you're going with true duals, dont get cutouts... if you're going with a full exhaust system, get the dual cutout y-pipe and electric openers.