Ok here is what I'm thinking....

Pentium 4 3.2GHZ processor $115
ASUS SKT .775 INTEL 945G M-ATX $100
Kingston 1G RAM (two of em') $82 (For both)
Seagate 500GB SATAII 16MB hard drive for storage $131
My current 120GB hard drive for Applications and OS Already have it
ANTEC NSK4400 Mid tower 380W power supply. $86
LG 18x multi DVD-RW $33

For a total of $547

Will the processor and memory be enough to run PS and process photos without too much lag? Anything you see that I should change or add? I will not be gaming so this is strictly for image editing/storing.

Will I need a video card or will the on board card be ok?

Thanks for the input guys. I'm not very hardware savvy.