Ok pros and cons for both. SSD's are fantastic but with only 120GB that would be best used as your operating system drive and maybe 1 or 2 games. They do increase boot time and loading times by a bit and windows runs smooth as a baby's bum. However you will fill the SSD in no time and TBH on most games I have played there is not much of an improvement apart from a few seconds quicker load times.
2GB vs 4GB VRam. As of now most new games when running on high settings will use nearly all of the 2GB VRam, i suspect in the near future games will use more and more VRam. It seems that now 3-4GB cards are the way to go however there is a significant cost difference.
Personally I would get the 770 4BG as in time the games will need the extra ram. I have found 1 or 2 games will drop FPS on my GTX 680 2GB due to the memory buffer being full. SSD's are getting cheaper and I would wait, you will get a better gaming experience from the better GPU.