The diamond bits I use are made by Lenox and are rated for metal. Yours are for stone and tile and probably have finer teeth. Both will cut aluminum. Yours will have issues with clogging the "teeth". I would use a water based cutting fluid to minimize aluminum sticking to the cutting surface.

If you are going to the trouble of installing a port, I would just thru-bolt. Helicoils, inserts, etc are used so you don't have to have access to the back side.