SATA II and Win 7.
Any major brand SSD drive will be fine. Barring any known defects or high failure rates for a particular model, I would purchase on price for this system. SSDs in general are very reliable and typically exceed published lifetime ratings. As one reviewer recently said, it's almost impossible to wear out a modern SSD under normal home use. Some types of SSD memory will last longer and/or provide better performance but usually also costs more. The Samsung 850 EVO is an easy recommendation for a budget drive.