Many vendors on this forum offer the Akra products - you could look in the sponsors marketplace section. You could also ask in the regional forum to see if anyone local to you can recommend a place to buy & install. Depending on how far you are from MA, you could go to Turner Motorsports to buy and have it installed.
The install is very easy but you would need some ramps at least. I'm sure the dealer would install it as well but they are likely to overcharge you on labor (I for one, would never get any aftermarket parts installed at a dealer). As for a tune or CEL's, no need to worry as it's just a muffler that you'd be installing and it won't affect any of the emissions equipment on the car.