Help with adding exhaust flanges

I have some Pacesetter long tubes and a Doug's shorty x-pipe that I'm installing once the weather gets a little warmer, but the Pacesetters and the x-pipe are both clamp-on. I've heard good things and bad things about clamp-on systems, but the thing I hear the most is that they come loose a lot, so I'd like some help figuring out what needs to be done to add some flanges on both the x-pipe and headers so that they bolt together instead.

X-Pipe Doug's Mustang Shorty X-Pipe (4.6L 3V 05-09)

Headers - Pacesetter 05-10 Ford Mustang 4.0L Long Tube Headers Parts - DragTimes.com