I hate to be the bearer of bad news but there is no way that a DSLR will outperform a webcam for imaging the planets. Even a cheap one. It just isn't going to happen. This is why webcam imaging has become all the rage for the moon, sun and planets. Very few other systems for ground based planetary imagery come even close unless you want to spend mega buck on adpative optics and very sophisticated imagers, with not much improvement.
Have a look at birds or icemans latest Jupiters you might change your mind about cheap to mid range CCD. And do a check of last years Jupiters that iceman was doing with a $170 Toucam.
I don't think I would be far off saying that these guys are up there with the best in the world when it comes to imaging Jupiter.
These are
birds latest attempts with a "webcam". Admittedly probably a grands + worth, but it way better than any SBIG could do. DSO and Planetary imaging are two totally different games requiring very different camera, software and processing.
If you can get hold of them have a read of Digital Astrophotography: The State of the Art, or Introduction to Webcam Astrophotography. They are two of the better books getting around at the moment, especially the second one.