Here's a thought- how noticable is the difference between SATA II at it's peak, and SATA III? In other words, in day to day usage will you really see a difference between that drive on a SATA II port compared to that same drive on a SATA III port?
I honestly don't know, hence why I'm asking. But I'm using a first generation 30GB SSD on SATA II right now and as is I'm not sure I could notice anything more, or at least anything significant, with a faster SSD. You may not need that controller and may be fine with your on-board SATA controller.
Think of it this way- that SSD will be able to keep up, and help improve the experience, when you do finally upgrade to a new motherboard and processor.
Over the course of this year I am going to start replacing some of my smaller hard drives with SSDs, and I'll be using the on-board controller. It will be an upgrade for me as they aren't going to be first generation SSDs- they'll likely peg the SATA bandwidth. Going off of your sig you don't even have an SSD- even running that Corsair off of your integrated SATA controller will be a significantly noticeable upgrade in performance.
Just some food for thought.