It is most likely that you have SATA 1 since SATA 2 was not shipped in mass until 2010, and the processor was released much before then, but I cannot be certain, since I do not know if Toshiba is using just the intel chipset, or adding on anything third party of their own. Also, you need the operating system, the BIOS, and the SSD to support TRIM. I know that Windows Vista does not support it, and I highly doubt your motherboard does. Also, 10,000 rpm HDD can max out SATA 1 bandwith, so perhaps just an upgrade to a 7200 or 10,000 rpm HDD will be sufficient?
Actually i just found some documents that say the laptop uses the GM45 chipset. which means that you will have a SATA 1 cable. so 10,000 rpm HDD will max out performance for you. However, you can definitley save battery life with an SSD