Actually a Mag drill will work on alum. There are two options, one is you can buy the vaccuum base for it, or the other option is get a nice thick piece of steel and clamp it to the alum. then magnetize the drill to the steel. I used this method for drilling my alum jig table and it worked perfectly, and all my holes came out perfect, drilled and tapped. I will post a pic later of my setup.
Here are some more pics of the table and how I setup the drill since ive been getting a few requests. I used bolts upside down as levelers. I got the ones with the wide heads so theres a lil extra surface area.