Spec looks fine, the only thing I would say is I dont know if you intend to overclock the CPU, but if you do you might want to buy an aftermarket cooler. These start in price from about £10 upwards.
You havent mentioned what operating system you will be using ? If its Windows XP or Vista remember the PC will only recognise about 3GB of the ram you have installed. Programs should be able to use all of it, so its not a problem.
For Windows to see all 4GB you would need to install Windows Vista 64. But some video editing suites have issues with 64 editions so probably worth sticking to 32 version.