The cases you picked are fine cases, just pick one and go for it.
As for the SSD, 64GB SSDs are indeed big enough for the basics, but that really will be about it. I have a 120GB in my laptop and I'm using about 91.2 GB, but I have a couple of games installed as well.
Since you're not a gamer, and you are doing multimedia encodes, I'd like to offer a counterpoint to your choices on the CPU and motherboard.
Go AMD for the system. Why? AMD chips are, believe it or not, very fast for media transcodes, especially if you do x.264 encoding. And to be honest, if you have 15 years of video to encode, you'll never notice the difference, but your pocketbook might.
Newegg.com - AMD Phenom II X4 965 Black Edition Deneb 3.4GHz Socket AM3 125W Quad-Core Processor HDZ965FBGMBOX
Newegg.com - GIGABYTE GA-880GMA-USB3 AM3+ AMD 880G HDMI SATA 6Gb/s USB 3.0 Micro ATX AMD Motherboard
The other reason I'm suggesting this, is that the integrated video that comes with that motherboard doesn't suck, and you can pocket the $200 and put that toward more storage or a better capture device(s). You don't need a high end video card for the type of work you'll be doing. We use a very similar setup at work with integrated video, it does a fine job.
Everything else looks fine, so those are my only recommendations.