Any mod ideas for my 99 cobra

I have a 99 cobra with a BBK H pipe [ with cats ] , Dynoflow mufflers and cold air kit. What should my next up grade be? I wanted to go with a supercharger like the K bell but it would cost over 6K to get it installed because my belts are not set up for a top mount supercharger. Anyone know of a good side mount supercharger for the 99-01 cobras? Whats the best computer chip for the cobra's? I need about 50-75 more HPs to beat my buddy in his stage 3 Roush. Thanks for any idea's.