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.
or you could check their website for outlets in your area.