i had a whole lot written here, but then after reading it, i decided to start over!
1. RAID0 is not really RAID at all, since the R in RAID is for REDUNDANT, meaning it is a backup of something. in RAID0, there is no backup in the array itself. lose a drive and you lose everything.
2. RAID0 is for SPEED, not safety. RAID0 allows slower mechanical hard drives the ability to more fully utilize the bandwidth of the dataport (used to be IDE but now is SATA2/3). a conventional hard drive, even the fastest of them all (usually the Raptors from WD), hardly scratch the surface when it comes to bandwidth usage. SATA3 drives are really nothing more than a marketing gimmick.
3. SSDs CAN be RAIDed, but you don't want or need to:
a. you don't WANT to because of the fact that the important TRIM command used by SSDs to maintain peak performance is disabled. without it, your drive/array will come to a crawl, which will mean you'll have to clean everything up and restore from a backup every so often.
b. you don't NEED to because SSDs are close to maxing out the bandwidth of the dataports. so, putting two of them together (which is expensive in itself), will only give you a slight performance increase (maybe). therefore, not a good way to spend your tech dollars.
c. RAID with SSDs have the same failure points as with a mechanical hard drive, and since SSDs are far more expensive than mechanical hard drives, you'll feel the pain pretty damn fast and hard when one goes out.
4. my opinion is to look at your current storage needs and get a SINGLE SSD big enough for it. for example, if your hard drive with applications and the OS takes up ~200GBs, get an SSD that's about 256GB-300GB+. DO NOT use the SSD to store your personal data (pics, vids, documents, backups, etc)...use a large conventional hard drive for that. also factor in future software purchases that could eat up drive space. be prepared to lose a few apps if needed to make space.
5. dealing with RAID PERIOD can be a royal PITA...either with SSDs or HDDs.
6. a SINGLE drive is preferable, i have found, than using one for the OS and one for apps. frequently, apps like office, visual studio, and flight simulator X, put crucial data on the OS drive and in hidden, nearly non-accessible folders. i found out the hard way that my FSX files were not backed up because of that, and i lost several months of work and training! plus it's so much easier to complete backups from a single drive than having to backup multiple drives.
7. if going SSD, make sure you research its performance and ensure that it matches with your intended usage. running games requires a different set of benchmarks than running a server or database.
8. with SSDs, ALWAYS check its reliability history and stability! these controllers are not all the same and you would be surprised at how SSDs from some big names can be real POS.
whew...i hope that helps!