Hey guys I’ve got a Rosewill RSV-L4312 case that holds 12 drives. I also have two SSD drives connected and one M.2 all used for cache. My motherboard is a Maximus hero IX and a 6700k processor. I built this using most of my older gear hence the Mb and processor type. The issue I’m running into is the hero only had 6 sata ports. I’ve already maxed them out and have two more drives on the way. I figured I would buy an 8 port pcie sata expansion used on eBay and right before I bought it I did a quick search to see if there would be an issue. I came across a bunch of posts talking about the need of flashing it etc. I wanted to reach out and see what the best plug and play solution would be for a reasonable price. I want it to be reliable but would rather not spend a ton of money if it isn’t warranted. All suggestions welcome. 
 

also not familiar with flashing so if there is one that doesn’t require that would be a plus.  

Anything LSI chipset based you won't have a problem with.  They should be flashed with IT mode firmware, but that's a painless procedure, and you'll be able to find ones on ebay already flashed (search for unRaid)

 

Just check the seller out.  Many of the ones whom ship from China are selling counterfeit cards which may or may not work properly.