Depened entirely on what you want to do with it and which s/w you wish to use. But basically any new PC costing over about £500 will do the job, at least to a basic fashion. Needless to say, the more you spend the better you can manage.
Look for a decent processor, preferably dual core or equivalnet. At least two seperate hard drive. onefor the OS and one for video. A halfway decent graphics card. Although often as not this is npot strictly necessary there are now proving to be manby apps that do make use of a good GPU so don't skimp on this too much. You'll need a firewire port. oh, and don't forget top budget for s/w. Depending on what you wasnt to do, the s/w may well be more expensive than the PC itself. Then again you might go Mac...
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