I might be buying parts for a new build sometime in the future. This is the first PC I've built since an A+ Certification class from high school, but I feel I've retained enough knowledge of the process. So far these are the parts I'm considering:
The i3-2100 is a hell of a chip for a dual core, but even so, I'd say go for an i5, especially if you want to get into video editing stuff, also some games do see a notable performance increase from quad core CPUs. Also the GTX 560 is, meh. You could do better.
That Biostar mobo isn't bad, but that money your paying for the extrnal sound card could be put into a higher quality mobo, which incidentally will have 7.1 surround support.