The DBK 21AU04.AS is more or less a 900nc webcam with long exposure, its great for planetary but thats about as far as i would go with it. If you want a real ccd take peter's opinion and get a used qhy8. Personally i wouldn't bother at that end of market and would save some more. Just getting a set of filter's for our dsi pro mono to play till i have the funds lol. In your case if you own a notebook i would grab a cannon eos to make life easier polar/drift aligning and also your imaging.
To get the best results though lots more work mono is the only way to go, if you go color you lose nearly 3/4 of the resolution due to how the sensor receives color. It really does get costly at this point from my research not experience, its kinda all in or not, like you could go for something basic but will soon be ditching it for something better.
Anyhow hope some more experienced people respond who can help you more, but don't impulse get the best of you
The camera at bintel you listed is a video camera for so you can exploure the sky remotely on a tv screen or broadcast over the internet ect, its not a imager so to speak.