I finally finished my NAS!
Platform: HP Micro G7 N54L
RAM: 8GB ECC
System disk: SSD mSATA KINGSTON SMS200S3/30G
Adapter for mSATA: Syba HDD SATA 6Gb/s + SSD mSATA Hybrid Drive PCI-Express x1 Card (SY-PEX40053)
Options for server: Micro Server Remote Access Car
HDD: 5 x 3.5" WD Red WD40EFRX 4TB + adapter for 3.5'' in 5.25''.
Result: I have great NAS 14.3TB (RAID5 software), remote manage (for full backup system) and very fast system (SSD).
OMV team, thank you very much!!! You are best!!!