Expantion Devices

[Donner]

Hello, I'm finally getting around to taking apart my old PC and turning it into a server. 

Specs: i7-9700K, 32GB RAM, Z390 AORUS MASTER, RSV-L4500U.

I want to put two M.2 SSDs as my OS drives with redundancy. Having two disables some of my 6 SATA connections, so I'm in need of some SATA expansion. I don't know a whole lot about them, but it seems a lot of people recommend the Broadcom 9--- HBA cards. Id have though Id just get some SATA expansion cards, but these HBA cards seem to be more recommended from what I gather. Through my reading the LSI 9305-16i and the LSI 9400-16i are what I'm looking for. I found a LSI 9400-16i on ebay for 108$ that comes from China. I guess I'm wondering if these are generally real or of they are fake/knockoff and if its any good. What do you guys use?

Any advice or recommendation is much appreciated!

Thank you.