What is best raid configuration for working with adobe premiere? or video editing for that matter?
SSD beats a WD velociraptor in all terms?
The achilles heel of SSDs is their sequential write rate - most modern hard drives can actually beat an SSD for writing large files, at least when the drive is not doing anything else and the file is being written to the outermost tracks of the drive.
For reading and writing large files, either SSDs or hard drives in RAID 0 or RAID 1+0 will give you the best performance. Avoid RAID 5, which has very high overhead for writes.