Though I'm not really a DSO imager as a rule, just thought I'd mention that nice DSO pic's can be also obtained with integrating video cameras too. Yeah ok..I'm pushing the video thing but it's just another option.
Here's my contribution to the Sombrero Galaxy clan using with a Mintron 13V1 integrating video camera at maximum integration mode of 2.6 seconds and RGB filters. This is a stack of 300 images per colour channel captured from S-VHS video tape with dark and light frames processing. Best of all is that it was taken from the obtrusive lighting of suburban Sydney.
If you'd like to see additional DSO pic's from video then check out my website:
http://members.optushome.com.au/ssmassey/deepsky.html