Look into Dynomax race bullets if your going wit straight through. they actually have tone to em and give a nice deep rumble. Sound better than SLPs imo. SLPs cost like $150 for just two "resonators". Dynomax race bullets are about $45 a piece
I'd say the Magnaflow X pipe aswell but since your on a budget.. I'd recommend taking the cats off and running straight pipes if that's what you want. Either way if you get it straight piped or get the Magnaflow X it'll be louder.
The ATAK's sound good but they're pretty expensive, well for me anyways. I'm going to order the Spintech super pro street 9000's pretty soon. My dad said he'd help me take off these mufflers and put the new ones on. I can't wait lol