SSD are really good to use as boot drives, so since you've already got one, why not keep it as just that?
All you have to do is have a second drive as a storage drive and make a few changes to your installation habits. It's not too complex really. With Windows 7 you can change the User account stuff to point to a different drive and you can choose to install programs to that same secondary drive.
Just recreate the Program Files, Program Files (x86), and Users folders (including subfolders like My Documents) on your secondary drive, then change the target location for all your user account stuff, like my documents, my pictures, etc.
After creating those folders I listed above on a secondary drive, right click on C:\Users\*MyUsername*\My Documents and choose properties. Select the Location tab and make it point to the secondary drive's My Documents Folder instead of your SSD.
That's it. Now do that for all the User account folders like My Pictures, My Videos, Desktop, etc.
On top of that, whenever you want to install a program, change the install location to your secondary drive. Instead of C:\Program Files\***whatever***, you'd change it to whatever your secondary drive letter is. If my secondary drive is X:\, I'd change all my installations to X:\Program Files\***whatever***
Now you won't fill up your SSD at all and you'll still be able to use it as a boot drive. All it takes is for you to pay attention to where you're installing stuff.