I've built 4 sets of pipes and a second set of headers with components from Speedway Motors. Straight-thru mufflers were sourced elseware. Sidepipes w/mufflers cost around $200/
pr.
IMO the best sounding open pipes are a collector with short turnout. Much deeper sound than the full length open pipe. They allow you to feel the concussion in your chest and legs when standing next to the car. They made the most power too.
Scott