the more the merrier. in your case this applies to the amount of ram and hdd capacity. i'd get at least 1 gb of ram and a huge hdd, preferably +250gb (there are some drives with even 16mb cache). i dunno if ur mobo supports sata, but if it does, that's the way then. ur vid card should be fine, and i think u can cope with the cpu.
i just recently read a review about video editing software and the one (can't remember the name
) that won adobe premiere among others rivals was actually really cheap.