Wakefield has some pretty nice anodized Heat Sinks they've spec'd specifically for big Bridgelux emitters, although there's certainly nothing preventing you from using them with triple stars or cranked-up XM-L's. The best thing about radial heatsinks is they can work in either up or down orientations without taking a thermal penalty. Throw in a Ledil Brooke reflector, and you have a pretty darn easy DIY LED source with excellent color, output and distribution....and it actually looks pretty good as well. Just tuck the wires inside the fins of the heatsink, and it's pretty 'spiffy' and clean. I use a few of these in my apartment, although this is the older W802. I use a cool-white version as an inspection light, and it's probably the best portable light source I've ever used.
Unfortunately Bridgelux is moving in a direction of higher voltage / low current which makes things a bit tricky now if you're planning on using more than a couple. Likely easier now just to plan on using a DC/DC driver on each emitter and running a 36 or 48volt DC driver at the front of everything. That way you could add or remove lights as you needed without affecting the others.
Darn easy solution for DIY though. As a diabolical idea I always though it would be cool to hang something like this in large numbers from a high, dark ceiling using thin, black aircraft wire as both the support and power leads. You'd have a fairly bright, zero maintenance light source that would appear to be floating in the air.