I have a Starlight Xpress Loadstar for sale. It is one of the most sensitive autoguider in the market and is considered the most suitable autoguiding CCD in the market.
You are able to get more technical information from:
http://www.sxccd.com/lodestar-autoguider
You can view images taken while guiding with this ccd from my Astrobin:
http://www.astrobin.com/users/ntk.thava/
If you are interested, please email me at
ntk.thava@gmail.com