Yes, flippy is right - we need to know what your budget is then hardware can be sorted out - but i have found the best place to get a very good computer that wont fail on you is at computer fairs - if you live anywhere in CT, or Mass or Rhode Island - There are PC fairs every weekend -
www.coganfairs.com - there is a schedule there - if you dont live around there - best suggestion for parts cheap would be at a PC fair - thats where i got mine - quite the beast for 750& without OS or moniter
good luck
-SImo