Need help determining what type of pc i need

My parents have offered to purchase a new computer for me because I have been reviving my crappy computer from near death for a long time (people screwed around on it). I am a graphic design major but I'm not computer savvy enough to know what exactly I need.

Im looking for a pc in which i can run demanding programs simultaniously
photoshop, illustrator etc.
large torrents
lots of pron

I need something with at least the following:
200-300 gig memory (out of the box)
2-4 gig virtual mem. (out of the box) with availible slots
a high end prosessor
read and write cdr/w and dvdr/w

I really need something that will last a decent amount of time.. and can be improved uppon when needed

and sorry if this post is all choppy, trying to multi task

Thanks