I have an 80 GB SATA3.0 OS drive and a 750GB SATA3.0 Media drive in my system. Seems to work for me, but heaven help me should it fail. The reason I have a 750GB drive in my HTPC is because my 500GB drive failed.
You may want to look into some sort of back-up solution for the media your store on your system.
As for the DVD Drive, looking at your case, it looks more like that a drive door rather than a bay shield. Meaning it doesn't come off. The only time you actually see the DVD Drive is when you open the tray to insert/remove a DVD. I don't think you're going to find one that has a silver/brushed chrome bezel. Just go for a black DVD drive.