@Ripper7620 Checkout RockStor instead, you seem to be looking for performance, in my testing it was about 40% faster with Raid 10. Others have found it to be 5X faster.
Getting high baseline speeds + adding a read cache is hard. With FreeNAS you'll have a lot of support for mediocre baselines speeds, but decent caching options. Though not as mediocre as unRaid's baseline, most people get around that by dumping money into dangerous caching solutions or quad 2TB SSD's.
I'm considering a unRaid VM to handle caching because setting up bcache on Rockstor is a pita.