Looks good. I'd pay some attention to keeping it quiet, because there's nothing more annoying than noisy fans whirring away whilst you're trying to watch a film. A case like the Antec P183 is a good start. Then you could look into an aftermarket CPU cooler, possibly a Thermalright with a slow 120mm fan, as the stock coolers tend to be quite noisy. The stock Antec fans are reasonably quiet on low speed, but if you wanted lower noise levels you could swap them for Noctua fans.
Hard drives: if it's just storing movies, the drive doesn't need to be especially fast but it does need to be reliable and reasonably quiet. I'd suggest something like a WD Caviar Green: spins at 5400rpm compared to the standard 7200rpm, which means it will run cooler and be quieter than most drives. Might be worth getting two drives or even one external drive for backup, as you're gonna be annoyed if the drive dies and you have to rip all the movies again.
As for ripping the movies: you need to decide whether you're going to store the DVD content as-is on the PC, or re-encode it to a format like x264. Copying the disc directly will take up more space (probably anywhere between 3-8GB per DVD), but will be quicker and allow you to keep the DVD menus, etc. Re-encoding will take less space (anywhere from 500MB to 2GB per film, depending on your chosen quality - about 1GB is probably a good compromise).
If you go down this route, bear in mind that encoding DVD video to x264 is pretty CPU-intensive at decent quality settings and could take a while. I'd reckon on an hour per film at least, even on the i7 which is a great CPU for it. (That's why I recommend some kind of backup!) If you just copy the discs directly you avoid that hassle, at the expense of using more disk space.