I've bought mine off TheArtofServer. You can ask the seller questions and they'll happily help. Not to shill but the guy is super passionate about the HBA business.
I currently went overboard and got a tri mode LSI which is quite pricey. But it allows me to mix and match SATA, SAS, and U.2/3
Broadcom 9500-8i Tri-Mode is the model.
https://www.ebay.com/str/theartofserver
For sas and sata only I have a LSI 9305-16i for my big server. The 9305 runs quite cooler, but you pay more upfront.