Oh and for both those end mills at those feedrates, you can max the rpm's at 4000

It depends on size and material of the tool you're using. With aluminium you want to be using a 3 flute end mill with about a 50-60 degree helix. Carbide would be ideal but you can use HSS. You want a step over of about 10% - 15% of the tool diameter and a depth of cut of about 1x diameter. As I say...