Cold air intake and full exhaust. Then there's always weight reduction.
You really can't get both hp and fm. The options I've listed, are ways to get both, but it's going to be so miniscule you'll probably not notice.
1999 Chevrolet Camaro SS (PC'd)
1994 Chevrolet Beretta Z26 Q4 (W41 M90'd)
2004 Chevrolet Silverado 2500 (4WD)
My wife's cars:
1971 Dodge Charger SE (stock and original 383 auto)
2004 Subaru Impreza WRX (kid-hauler)