The top model mobos from Asrock, Asus and Gigabyte that are specifically designed to power the FX-8350 or higher power consumption CPUs such as the FX-9370 and FX-9590 are good mobos for 8-core FX processors. Asrock has three suitable models in the Fatality 990FX Professional, the Fatality 990FX Killer and the 990FX Extreme9. The above mobo makers list the CPUs supported for each model mobo they sell on their website so you know for sure the FX-8350 or other CPU model is supported. Gigabyte also has three proper FX-8350 model mobos in the GA-990FXA-UD7, GA-990FXA-UD5 and the GA-990FXA-UD3. It's easy to confuse their model numbers but you need an "FXA" UD-7, UD5 or UD3 model.
I don't use or recommend Asus mobos as they are the only brand of mobos that I have had fail in 25+ years of building PCs. Asus also uses other companies to produce many of their mobos so there is no telling what the quality will be from one mobo to the next. My experience with Asus customer service on the first defective mobo that failed within three months, resulted in Asus sending a hand soldered repaired dirty, unacceptable replacement mobo that I returned to them and purchased a Gigabyte mobo that is still running fine today years later.
Note: FX-9000 series mobos require a special mobo that can supply 220w vs. the std. FX-8000 series CPUs that only need 125w. FX-9000 series CPUs also require a HSF or other cooler capable of cooling a 220w CPU - which is almost twice the heat load of a std. FX-8000 125w CPU.
I am currently running the Asrock Fatality Pro with an FX-8350 overclocked to 4.7 GHz. that is bulletproof reliable and runs 24/7 without any issues. I have not used the "Killer" model which was released after the Fatality Pro model but I have no reservations in recommending the Killer model for the FX-8000 series CPUs as Asrock has done excellent design and engineering on these mobos.