well first off dont go to a AAA shop as they're not allowed to install parts the customer brings in. If you know what exhaust you want go buy it then just find a shop in your area that'll install it. Not sure any shop will warranty a part other than the manufacturers warranty. Just call around.
Our point is that its such a simple thing to do, any shop could be trusted with the work. And no shop springs to mind because its something most of us would do ourselves so we haven't sought out a shop that'll do it.
Also, you should have started your own thread about this.