I am wondering if the AEM CAI is oil free and if it has a heat shield. Also, would a Simota Carbon Fiber Intakeproducesimilar results? I can't seem to find this info on other sites. thanks.

As the Mazdaspeed CAI (designed/built by AEM,)itdoes come w/a heat shield, but if you buy it as an AEM it does not. They both use a synthetic filter, not a K&N style oiled one.
As for the Simota, I have a friend who has one and the rubber connectors they use deteriorate from engine heat in fairly short order. They should be using reinforced silicone rubber like most of the better brands do.

What are you going to put an AEM on? If you're thinking about a 6 I highly recommend the Mazdaspeed CIA. Little pricey but a very clean/nice setup.

i think that the ms intake line is discontinued now. i am sure that you could find one used, but it would still probably be just as expensive.

The Mazdaspeed IS the AEM.They are one in the same, only AEM offers more finishes.