RAID 1 is two disks... If you want mirroring with four disks, you'll need to use some form of multilevel RAID setup, such as 1+5 or 1+0.
Also, data recovery companies love people who think their data is "perfectly safe" as a result of running RAID
That said, I suspect running RAID 0 on SSDs is less insane than doing so on HDDs, from an Oh-no-my-data-is-gone! perspective. While both can fail in many different exciting ways, hard disks have an interesting fondness of failing completely with no warning (SMART does NOT always provide warnings), while SDDs, apart from those caused by, for instance, fires, should slowly degrade as the FLASH cells wear out.