I wouldn't go deleting things from System32 unless you know *exactly* what you're doing. And I mean not following someone's internet post, but actually understand what the file does that you're thinking of deleting. System32 contains thousands of critical and shared libraries that programs and Windows need to function.

In regards to your WinSxS directory, read this article: http://support.microsoft.com/kb/2795190

If you're comfortable making your updates and service packs permanent and uninstallable, follow the directions. Generally, in my opinion, if your computer has been running fine for a while, there's nothing wrong with making your Windows state permanent. Note that this does not mean you can't uninstall programs or use System Restore.

Windows also includes a Disk Cleanup utility that can reclaim space.

Any chance your computer supports more than one internal hard drive? Is it in your budget to get a bigger SSD -- assuming it's not some proprietary SSD card?