I think APS still use a Unichip piggy back computer which I don't feel is anywhere near as good or as versitile as the CAPA flash tuner which can be bought at numerous outlets.
A new set of valve springs, larger injectors and air intake coupled with a custom tune using the CAPA flash tuner should have you smiling.
In fact just a CAPA flash tuner with a custom tune would have you smiling for a start.
CAPA has a sponsor area in these forums where you can ask for advice on the unit and how best to purchase one.
http://www.fordforums.com/f662/
or you could check their website for outlets in your area.