SSD do not defrag at all. So don't waste your time fragmenting it.
You would still get the benefits of fast booting as long as Windows is installed on the SSD. Two SATA drives generally don't take longer to be detected than a single.
Your idea of sacrificing drive capacity for speed is a good one as long as you physically have room for both drives.
2006 Lancer Evolution IX MR In-Dash PC Project - WIP
Installation/Fab/Assembly (Revised v2):
video files all on the ol' movin parts drive.
Thanks for the response.