The whole point of getting a 120GB SSD is to install the OS, programs and games on it. I have a 120GB Vertex 2 and with Windows 7 X64 Ultimate, Office 2007, programs and 10 to 12 games I have about 38-40GB free. Just uninstall games when you are done with them. Very easy especially with Steam.
Get the cheapest drive you can for storage.