I haven't started my build yet but if I started today I would probably use 80/20 erector set to not only hold the heatsinks together but also provide a solid structure for suspension. 80/20 also have black anodized profiles that look nice.
Oh, I didn't know it came in anodized black as well. That was something I was looking for in my heat sink - anodized in color. Black is likely what I would have gone with, but other options would be nice too. One of the builds in the build list used the 80/20 as the heat sink/structure and it made a very attractive fixture. I'll have to browse again to remember which one, though.
Which reminds me of another factoid I recall from my research...
EDIT: it was Fizzout's build that used the 80/20, for those who want to check it out.