The library is usually not that many MB's, so there is no reason to try to move this, if it's even possible. But I guess you're talking about your media library.
If that's the case, It would be nuts to save this on a SSD disk. Way to costly. If you have data up to the 2TB limit I would go for a single silent and energy efficient one. No need for super low seek times and transfer rates on Music and video storage. Samsung SpinPoint F4EG 2TB is a great disk! It spins at a low speed, it's very resistant to read errors, and has plenty speed for storage. I have 9 of this (soon to be 18) in two raid arrays in a 24 disk SAS expander
If you need more space, then consider a NAS unit for more of this disks. Or a but cost effective huge Norco solution like nuts people like me
What you must avoid purchasing is this 7200 RPM disks with spindown. It's CRAZY annoying to wait for the spinup on this disks every time you start playing music or watch a movie.