best muffler options with shorties and h pipe with high flow cats

right now i have stock headers, an off road h pope that doesn't fit worth a darn, and a flowmaster catback with 3 chamber flows in it. it sounds okay, id like a little more volume if anything.

im getting ready to go to a bbk catted h pipe which has two high flow cats in it. im going to start driving this car every day to work (30 miles each way) and to get some of that volume back id have to go to 2 chamber flows but them im afraid im going to get drone.

im okay to get new muffers and use the flowmaster catback too right? as long as the mufflers i get are same dimensions?

do all the 40-44 series drone?

what are my other options-magnaflow? dynomax?