I have read that some people say either go with the borla proxs or flowmaster 50 series. My local muffler shop doesnt sell borla because he says its an inferior product and cost more and said he hasnt put flowmaster on a rado/canyon yet. He wants to do a magnaflow muffler installed for 169. Does that seem reasonable? Or should I go with borla or flowmaster? Anybody in DFW area have a good shop they trust?