If I remember correctly, the main differences between the K100D and the K100D Super are that the K100DS added the dust removal feature and autofocus compatibility with HSM lenses (DA*16-50, DA*50-135, DA17-70). Here's another review for you to look at:
Steves Digicams - Pentax K100D Super Digital SLR - Hands on Review
Personally, I think you should see about spending a little more and picking up the K10D. With all the features it has, you won't grow out of it anytime soon.
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