I have a 64GB SSD in my system with 8 CC Tuners. I use a HDD for recording/buffering. While life of the drive is a minor concern, I mainly do it because the SSD doesn't have nearly enough space to be useful for HD DVR storage.
FWIW, my understanding of the wear-leveling algorithms means that if you have an SSD that is mostly full, and you write heavily to the "free" portion, the wear leveling algorithm will significantly reduce the overall life of the drive as it shits data around on the drive to keep one spot from getting worn out. The thing to remember, that the hypothetical of rewriting the entire drive from beginning to end, 24/7 is actually the best case scenario in regards to wear leveling (as wear leveling wouldn't even be used in that scenario) A much worse usage case would be if your SSD is 2/3 full, and the remaining third is rewritten constantly which will cause the wear leveling to constantly shift the "static" data to different places on the drive, cause actual writes for every one requested write.
Having said all of that, it still likely won't reduce the overall life of your drive to a point it will fail before you retire it in lieu of some newer/better/bigger/faster drive.
RAID protection is only for failed drives. That's it. It's no replacement for a proper backup.