Nukem posted the likely-specs on SC11's other thread as a Lenovo
. (I've swiped Nukem's link here.)
It looks like it uses an IDE DVD-R but has 2 SATA connectors, meaning "2 SATA HDDs, max".
Also, this is a SATA-II connection. If I was buying on a budget, I might be able to find a cheaper SATA-II drive instead of the newer SATA-III (or "SATA3"), but I'd buy on price-alone. If the SATA3 was cheaper, I'd get that because, after all, it could be transferred out, sometime in the future, to the next box and it will deliver better data-thru-put.