Well, for a video editing rig you definitely want to go with a quad core CPU. The Q9550 offers qreat performance for a reasonable price.
You don't even have a ballpark budget estimate? Will video editing be the computers only purpose? Will you also do any gaming on it?
You'll want at least two big, fast hard drives for working with video. Having the source and destination on separate drives really helps. The WD6400AAKS or WD 1TB Black edition drives are both great options. You might also want to look into a RAID 10 option to offer good performance and data redundancy since this will be your source of income. RAID 10 will require four drives.