Apparently (and this info is from actual Coyote owners), a Coyote will make a solid 500whp with all the "bolt ons" boss intake, aftermarket cams and a good dyno tune.
Maybe start with the Boss intake and go from there if you've already got the basic bolt ons?
2000 Mustang GT Steeda #0048
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.