If you are planning to build a RAID 0, consider using an
Depending on what your requirements are, you may find a better bang for your buck with just one SSD.
Also, higher RPM rotational drives (e.g. WD VelociRaptor series)
or hybrid drives (like Seagate Momentus XT) may be interesting, depending on your particular usage patterns.
As the capacity requirements increase, two things happen:
The price difference between an SSD and an array of rotational drives increases.
The performance of an array of rotational drives increases, because more spindles mean more parallelism.
This does not really apply to SSDs because just two or three SSDs would saturate their controller.
So for a large capacity storage a RAID 0 or even RAID 10 array would be cheaper and
can still meet the performance requirements for most any practical application.
If you do not need large capacity, consider a single SSD instead of a RAID 0 or two SSDs in RAID 1 instead of RAID 10.
Also, because RAID does not improve minimum access time, an SSD is by far the best choice for heavy random access.