The motherboard you have selected has six onboard SATA ports that you can use, currently you have nine drives, are all your drives full? If you are unable to consolidate your current system, in other words reduce the amount of physical drives, then you will need a HBA. I would suggest looking on eBay for a Dell H310 flashed to IT mode, or you can flash it yourself, it's pretty easy and their are guides on this board on how to do it. You will need two breakout cables and the card can support up to eight drives and has no issues with unRAID. The CPU you have chosen is entry level, if you want to explore dockers and virtualization you will need more cores and so a bigger CPU. If your budget can withstand it, you may want to look at something like an Intel i5-8600. I would also suggest reducing the number of smaller drives you have in favor of larger ones, so consider getting perhaps a 6 or 8TB drive for parity and eliminating the 2TB drives, replacing them with 4TB drives. The 2TB drives will be the bottleneck in your system as they are the slowest drives. Also consider an 500GB SSD as a cache drive, this is necessary if you want to play around with virtualization and handy for dockers too. Consider a UPS for your system, unRAID has native UPS management, something like an APC, something like this is all you need ( https://www.newegg.com/p/N82E16842301701) otherwise your parts list looks good.