Bang for buck + Emissions compliant in MOST states =
Catted DP OR a stock downpipe with ONE cat remaining and ONE cat gutted
De-catted Up Pipe or aftermarket up-pipe with no cat
Opensource Tune (or Cobb AP for comfort) + custom e-Tune from a well regarded forum member
You are looking at ~50whp and 80wtq over stock with this combo, for anywhere from $300-$1000 depending on your route.