It wouldnt worry about running out of space on the SSD for your steam games, its easy to move the less played games to another drive and use junction links to make steam think its still installed in the original location.
I already do that for my games and it works flawlessly.
Take a look at this utility I use that integrates with windows shell (explorer) to make it easy as point and click!
http://schinagl.priv.at/nt/hardlinks...kshellext.html