SSD for Website design/setup ???

Hey guys,
Need some advice here,
I need to get a new hard drive for my 2nd PC that the wife uses to manage, setup, modify etc, her website store.
She is using excel for updating 20k products pricing/availability then uploading to the server. also uploading/re sizing product pictures. constantly downloading very large files, modifying them, uploading them and then deleting them from the hard drive, then next week do it again.

Im not sure if a SSD is good for a application like this or is she better off to stick with a WD 640gig Black Edition HD? the faster the HD the better to process all the excel files and photos, but also needs to be rock solid.

Thanks for any/all advice you might have here

Ken