Like the age old saying - NOW or LATER

If you want to go for the biggest gains you can feel now.

Then go for the Pulley & Tune (pulley was not on your list)

If you want to build mods that will help you later

Then go for the Heat Exchanger, Pump and Intake Spacers (but only if a pulley is on the horizon)

If you want looks

Then go for a set of Eibach Springs (but you could trim your own and save $$)

A quick jolt in the butt (but no real gain)

Then go for that Sprint thingey

The rest will offer you nothing until you are ready to go beyond what is mentioned above. (Y-pipe, plug wires and Thermostat)