This sounds like a fun build, do the MotorDyne 5/8" spacer now you'll be able to use it later. Want more sound Art pipes are the best idea, sadly they're back ordered several months. "Good Luck" with this project!
Gary

 

Spacer for sure, but skip the CAI and just get a Z-tube and a better filter. This car's intake is already pretty efficient, so you might not even notice much with a CAI. In fact, you may lose power.

For the spacer, I assume Gary C meant a 5/16" not a 5/8". Motordyne makes a 5/16" which gives you a nice increase throughout the RPM range. They also make a 1/2" which gives you a tad more at the top end at the cost of some power down low. Great if you're going to be running WOT on a regular basis, but the 5/16" is much more useful for most people.

 

Z tube with drop in k&n,and suspension done, still waiting on my md spacer....now on to wheels!