Got another idea for you Fluke. Remember those one hole stoppers from science class? They are about an inch high, easy to find online, and cheap. The rubber might give some nice isolating qualities as well. I have seem them in black, and occasionally white.
... just a thought.
If you want aluminum, you should be able to get a chunk of fall off (scrap) from a metal yard. Most steel yards also sell aluminum. Ask if you can come down and look through their scrap pile. They will usually charge you by weight. I have seen and used solid Al round bar ranging in diameter from 1/2" to 6". The metal yard will be able to cut 4, 1" disks off of something for you, and charge you a buck or two per cut. You can make your own divot with a drill bit. Use a little sandpaper to smooth out the cuts and soften the corners. Finish sand with steel wool for a nice brushed look and your stylin'.
A metal shop will most likely have a minimum charge to do exactly the same thing I just described. Or you might want them to use a lathe to make a fancy divot, or some detail stripes around the lift... either way it is easy work and shouldn't take a pro more than an hour for labor (for the fancy version).
Good luck,
Funk