I would not do RAID on a dual SSD array at this stage of the game.
If you feel you really must get the boost an SSD provides, I think Dormouse's suggestion is a good one. I'd go:
SSD = System (i.e. boot + apps)
HDD1 = UserData
HDD2 = Backups
Boot from the SSD and only keep your OS and apps on it. Tune it and tweak it until you've got it exactly the way you want it. Then image it over to HDD1. Re-image (as soon as it's convenient) after any major changes. And keep two previous boot disk images.
Use HDD1 as your regular data storage space.
Backup HDD1 (including boot images) to HDD2 using the usual eclectic mix of synchronization, backup, and image strategies. Mix & match to get the best fit for what's being backed up. (Maybe not an ideal approach for the average
guy on the street. But that ain't us, so no worries.
We can handle a little extra complexity in order to get far better efficiency and reliability out of our backup plan.
FWIW I'm synchronizing more often than I'm doing traditional backups these days. I like having two immediately usable copies of my files. And my data footprint is now big enough that what I think of as a traditional backup simply takes too long and is too inefficient. Plus, I really don't trust most backup software. It's almost a truism that the one time you absolutely need to get something restored, your backup program will abort about half way through with an "archive corrupted - unable to restore" message.
I've seen that happen with freebie home and
thousand+ dollar enterprise backup software...
Not to say I no longer set up 'old style' backups. Many of my clients need to have an 'approved list' backup program installed on their network for insurance purposes or industry "compliance" regulations. But more often than not, it's the simple copies and synchronized directories stored on a second drive that saved the day. That's how cloud backups basically work. And that's where it will all be going in a few more years anyway.