Don't you spike when you get an upgraded ic and don't have a tune?
If so, go with the ap, that way you see gains right away and make sure your car is running properly and then once you get the ic you will then been able to have a tune for you car since you already have the AP. I say AP first
That's what I'm doing. My next mods are tires first b/c I want to get power to the ground. Then AP, dp, and FMIC follows.
AP is first so I can tune my other mods as I get them. That's what makes sense to me