Win7 64 is a good robust system. A quad core processor will indeed get used, and I'd say you could benefit with a minimum of 8 GB of RAM. A graphics card with 512 MB or so -- just make sure you don't use an internal graphics card, because they "share" memory with the system.
And, two internal hard drives -- a system drive with plenty of space and then a large second "data" drive for photos, other documents, and non-essential programs, and the Camera Raw Cache (that you configure in your Photoshop Bridge Edit/Camera Raw Preferences for both location and size. The default is small -- set the size to significantly larger. This can make a difference, especially if you install Lightroom, which shared the cache with Camera Raw.
And then, set the data drive up as the place for your Photoshop scratch/Windows pagefile location so that your system drive doesn't get overloaded. Make sure you leave a lot of free drive space on the data drive.
I've never used an SSD card. I gather their fast but limited. I've heard that it's not a good idea to overload them, but I can't give any details or speak with any "know it all-ness". You might want to read up on them if you want to buy into one.
Not knowing what you have presently, I'll just advise that you plan some things ahead of time -- an external drive will give you a place to offload parts of your library that you are no longer actively processing onto to ensure that your data drive does not get overloaded.
And, last but not first, a good size external drive as a backup drive to use regularly!