The GTS 250 is the same thing as my 9800GTX+ it is just rebadged and it is getting a little weak at anything over 1440x900 resolution. It is NOT really well balanced. An HD 5770 would be a better choice or best would be a HD 5850 if you can afford it. I can not really recommend Nvidia as Ati has more " bang for your buck" at least right now.
Also an SSD will do nothing as far as making games play any better. It will only decrease load times.