I assume the VAIO Z comes standard with RAID 0 because they use SSD instead of HDD. Since SSD have relatively small capacity two SSDs are RAIDed together to provide a larger single logical drive. There should be nothing special you need to do.
What would be the purpose of having two 64GB RAID 0 drives as opposed to one 128GB SSD? Like, why didn't Sony just stick a single 128GB SSD in their notebooks and opt for two RAID 0 drives?