If you run into any cast aluminum everything will change, below is some general helpful things that come to my mind
First I have almost done away with buffing, a good grade of aluminum along with a etch gives a nice color. If you do want to buff the parts look thru the caswell buffing manual, it has lots of good info
http://www.caswellplating.com/buffs/buffman.htm
For blast if you want that course rough finish I suggest aluminum oxide medium grit, I would choose around a 220 grit. You can look online to see what blast cabinet wil lwork well for you, I wear a dusk mask when blasting... just do not use sand
You will need to make your connections to your work piece (part being anodized) perfect, and have a way to do this every time, this is where most parts fail the connection point. I suggest the caswell sput welder, and some Titanium spring wire to make some spring clips from.
Hope this helps
Clint