I would probably just go to a local exhaust shop and have them add the resonators. coz really its an easy thing to do and you can choose what brand you want, magnaflow, vibrant ultra quite ect.
MR-S with a 2zz swap and mods
EVO X MR - Phantom Black - Ti Exhaust - Ti UICP - AQM Intake - Sold
Z4 M Coupe - H&R - RE Diablo - RPi - Tekarbon - Sold