Well you might as well while you have got the chance.. I find if you keep on top of it and say do it every 3-6months it's never that bad.
Hows the PSU coming? Have you sourced one yet? I'll keep my eye's open and if I see any deals I'll let you know..
Have you checked this site out?:
Newegg.com - Computer Parts, PC Components, Laptop Computers, Digital Cameras and more!