Help choosing hardware for Plex server

[xylcro]

For the last couple of days I've been researching a new Unraid server build to replace my current Dell R510 one. The Dell R510 is going to become my backup server. I've been looking at a ton of motherboards but just couldn't really figure out the 'best' choice.

Mainly what I want from this server is storage, I have my eye on this InterTech 16 bay chassis, now I just need some hardware to go with it.

Since the chassis is a 16 bay the motherboard does need to be able to handle 16 drives, plus 2 for cache. 

I do already have some hardware that may of may not be sufficient, but I honestly don't know.

Hardware I already have:

• Quadro P2200 (for HW transcoding, so new server doesn't need to be Intel)
• Asrock Z97 Extreme 4/3.1 (my old PC)
• Intel Core i7-4790K
• 32gigs of RAM

I've wanted to use this hardware but I've read on the Asrock website that when all PCI-e slots are populated the slots will be x8/4/4. 

The chassis has 16 drive bays with all 4 backplanes having its own SFF-8087 connector , plus 2 cache which means I can plug the first backplane in the first 4 SATA slots with a cross-over cable and the 2 cache drives in the remaining 2 SATA ports. That leaves the other 3 backplanes. I can either buy a SAS Expander (I also already have a Dell Perc H310 flashed in IT mode somewhere), however I don't really know how that works since I want to use the last PCI-e slot for a 10gb NIC. Or I can buy a 16x LSI HBA and still use the last pci-e slot for the 10gb NIC. I however don't know if it's going to be bottlenecked by the x4 speeds, I don't know a lot about that. If the stuff I have won't work, any recomendations for new hardware?

Thanks.

[WETAFROMAN]

Just about any newer motherboard and processor should do the trick for you. My new build mentioned below would work but its a little over kill if you are only running plex. I am running multiple VMs plus dockers like plex.