For mobo information check these links to the intel website out.
Moving your entire PC to a new case isn't too difficult but since you have to disconnect and reconnect everything it's pretty much like building a new pc, so be sure you've got some one to help you if you need it.
For your video editing, you should definately look into getting a second hard drive, at least 40 GB. If you're doing a LOT of editing, 80-120 GB would be better since .avi files take up a huge amount of space.
Rule of Thumb: when searching for information on hardware, always check the manufacturer's website first.
Good luck with the new system!