FreePBX on Shuttle DS437 and SSD

Recently I purchased Shuttle DS437 and SSD for digital signage project. I like it and I’m thinking to get another one to build PBX appliance based on FreePBX distro. In the past I always used SuperMicro products. I don’t expect any problems, but I would like to hear opinions about HDD choice. SSD, yes or no? What to do for redundancy? mSATA and 2.5" SSD in RAID-1 (would it work?), mSATA and standard 2.5" HDD (for log files, voicemails and backup only), SSD only or 2.5" HDD only?

DS437 is compact, fanless and has only one SATA port, but it accept mSATA card too.
If I go mSATA and 2.5" HDD I could use rsync to copy mSATA to HDD and vice versa, maybe couple of times a week. Keeping log files and voicemails on HDD and backing them up couple of times a week to mSATA SSD would reduce number of write cycles, extend life of SSD and improve reliablity of the system. Also, if any of those two fails recovery time would be minimal. Not sure how mSATA SSD and standard HDD would work in RAID-1. Anyone tried that? If I get bigger HDD then SSD then I could have additional partition (not RAID-1) on HDD for voicemails and log files only.