Get whatever sounds best to YOU. Get on multiple vendor sites, see what is in the pricerange you want and then look up on youtube what that sounds like and go from there. You'll get a million answers, none are right and none are wrong. If you are worried about which one makes the most power, for a bolt on car they are all within 1-2hp of each other.
2000 Mustang GT Steeda build #48. Bolt ons, suspension, Novi 2000.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.