You'll want carbide burrs that have more space between the cutting edges for aluminum. I highly suggest using a cutting wax on the burrs to keep the aluminum from "welding" itself to the burrs.
I'll get some suggestions for burrs and cutting wax after
Industrial Supply Equipment from MSC Industrial Supply is back up ( scheduled maintence on the tool supplier's website )
Are the die grinders and wands ( better ) 1/8" or 1/4" diameter ?
Jeff