Yes, both should work just fine in an Aztek. You will need to thin it for airbrush use. Acrylics can be thinned with water, alcohol, or the manufacturer's own brand of thinner. Enamel can be thinned with turpentine, mineral spirits, or the manufacturer's own brand.
I would recommend that you look into the use of a respirator, especially if you plan on spraying enamels. They can be hazardous to your health. Here is a link to a thread on them that was just started today: http://www.finescale.com/fsm/community/forum/topic.asp?TOPIC_ID=22628