I have a 170MB PSD file
here that contains three full resolution layers. One of 30s, one of 60s and one of 300s centered on the Orion nebula. The layers are strectched, unsharpened registered stacks so you'll have to do your own sharpening/noise reduction/contrast. If you want to have a play with it all and see what blend you can come up with for the core and other areas of interest. Just post the result in this thread it'd be interesting to see what people come up with.