TTI-Doug Headers
they have the 3" collectors wish will fit the rest of your exhuast slightly better but you will probably need to work some anyway to make your exhaust fit with the new collector location.
thermal barrier or just ceramic coated, well the diference is that the thermal barrier is there to keep the heat inside the tubes,adding velocity to the pulses as well as keeping heat out of your enginecompartment meaning you will make more power since the air will be colder. it also saves the tubes alitle, mild still gets kind of hard welds get more brittle when being subjected to extreme heat and cool downs over and over again