I would highly recommend saving a little more and get an 80+ gig SSD, Even a larger capacity, older SSD would be better. Biggest diff beween Sata II and SATA III SSDs is sequencial read/write performance - least important matrix for a Boot + program drive.
Afterthought, Spring for one of the Seagate hybred drives (internal 8 Gig SLC SSD), and wait to buy the SSD - Price will decrease, and / or, performance will even be higher.
If it is available in your part of the world, here is my standard recommendation.
If reliability and stability is a major concern, then I recommend Samsung. Samsung was awarded contracts to supply Dell, Sony, Lenovo, Apple and other off the shelf brands with OEM versions of their 470 Series SATA 2 3Gb/s ssd's. Eventually the 470's were released for retail sale to consumers. There have been no major issues reported. The 470 has an absolutely stellar record.
Then Samsung released their 830 Series SATA 3 6Gb/s ssd's as successors to the 470. The first ones were OEM versions for Dell and the other off the shelf brands followed by release of retail versions for consumers. The ssd's are Samsung's own design with their own components and firmware. It looks like Samsung got it right again.
so far from least to best performing one based on experience.
corsair force gt (these are great but had problem where 2 of them die out)
corsair force 3 (so far never had problem with this, just some update and all are great)
crucial m4 and intel 510 (these 2 are badboys since i bought it not even once did I ever encounter any problem besides the urge to get 4 of these in raid or something)