actually, dont buy a dell they break ver easyily
if you really want to get a pc i highly reccomend this website
www.overclockers.co.uk you will get ALOT for your money and there are alot of reviews of the full systems you can buy.
for graphics design, music and even now gaming any new mac with the intel chip will be ok aslong as you have sufficient memory etc, you can get a program called parallel desktop which lets you partition your mac HD and install a windows operating system on it, it will be good for running most normal windows applications and even some games but not new high end games.
and if your a student you can get discount on the apple website, www.apple.com then look for students at the bottom of the shop page.