I would grab a 1100D while there only $328 and a cheap notebook to help you more out as a beginner. But If you want a ccd go with a mono and get some filters to learn the art and basic's for future investment in a nice ccd that's of high res and spec. It all comes down to $'s and thats the worst part as a TEC cooled unit is going to knock major noise off long exposures and really don't start cheap.
You could get a Atik 16IC for $599 though its a color and because of the way a ccd receives light your images won't get the quality of the mono because it takes 4pixels to give a color see image attached. It's looks like a great cheap cooled ccd though for the entry level though. Problem is you can see how price is a big trade off for what you get, once you get to around 2K you can really get something that will give results at a nice resolution. That's why i'am starting with my TEC modded dsi pro, its cheap to learn with while i save for a imager that gives me results and resolution which i can enjoy. Really though my 1100D blows it away resolution wise, though the sensitivity and noise from the ccd is far better then the 1100D. My plan is to save for a QHY-9 mono, though as you can see at $2300 they arn't cheap lol. It really comes down to budget and at $600 i would look for a used mono to get you started put with be it a dsi pro 1/2 or a qhy8 color if you want a OSC. There's nothing wrong with OSC's though your never going to get the results of a mono and filters and half the time dslr can be a better option price wise bang for buck.
Things to look for are high QE, low noise, sensor size 569x734 ect, pixel size bigger is usauly better noise wise, if its cooled for lower noise and ADC bit rate though most should be 16bit.
Was just looking at this if your hell bent on a ccd with the money you have
http://www.bintel.com.au/Astrophotog...oductview.aspx .This and a set of meade filter's can get from ebay new $60 would get you started if it all must be new. On the up side you have a nice guide cam for later on to
