You don't need a RAID array for a simple poker PC, at least not for performance reasons. Any modern SSD will be fast enough, assuming it's connected to SATA3 (6GB/s). If your board lacks SATA3, go for a dedicated controller card to gain max performance.
http://en.wikipedia.org/wiki/RAID
Quote:
RAID 0
RAID 0 (block-level striping without parity or mirroring) has no (or zero) redundancy. It provides improved performance and additional storage but no fault tolerance. Any drive failure destroys the array, and the likelihood of failure increases with more drives in the array.[5]
RAID 1
In RAID 1 (mirroring without parity or striping), data is written identically to two drives, thereby producing a "mirrored set"; the read request is serviced by either of the two drives containing the requested data, whichever one involves least seek time plus rotational latency. Conversely, a write request updates the stripes of both drives. The write performance depends on the slower of the two writes (i.e. the one that involves larger seek time and rotational latency). At least two drives are required to constitute such an array. While more constituent drives may be employed, many implementations deal with a maximum of only two. The array continues to operate as long as at least one drive is functioning.[5]
RAID0 uses 2 drives to spread the data, so this makes things faster but not more fail-save. In fact, if one of the drives crashes, the data-parts on the other drive become useless as well. If anything, go for RAID1 for safety reasons. Not that you'd have to though - modern SSDs are just as reliable as HDDs, if not more.