I have Photoshop CS5, and it works fine on a 4 year old PC with a lower spec than yours. My comments would be: Graphics card OK but maybe a bit more memory on it.. I would also suggest a second HD either built in or in a removable caddy, and a USB Hd. The second disc could be used in periods of intense activity as a second scratch disc, although with the RAM you will have it may not be needed, but in any event backing up your photos and music is vital. Also do look at other threads on monitors for photography.
Also wait for comments from hssutton!!