That's interesting, 17-X is no longer listed. After a bit of digging around, it seems the Clevo 17 SB-E chassis has supply issues. It's not just Origin, but also some competitors with similar products that are showing out of stock or delisted.
No worries, 17-S Pro is still plenty capable.
Dell Precision M6700 is worth a look at as well, they have far superior display options (100% AdobeRGB 10-bit IPS!) alongwith upto Quadro K5000M if you need Quadro. Like I mentioned before, K5000M is faster than the desktop Quadro 6000! For general Premiere Pro CS6 work, 17-S Pro will be better value for money.