Yet Another Build Review

I've read just about every build suggestion on here & have several pages of notes, but this is my first build so I'm still a bit anxious about it. I'm hoping someone with experience can look over what I've got here for any obvious flaws. 

Case: CHENBRO RM41300-FS81 - http://www.newegg.com/Product/Product.as...6811123178
Mobo: ASRock Z170 OC  - http://www.newegg.com/Product/Product.as...6813157649
CPU: Quad core i7 - http://www.newegg.com/Product/Product.as...6819116987
GPUs: 4x  GTX 980s - http://www.newegg.com/Product/Product.as...6814133563
RAM: 16GB DDR4 (2 x 8GB)
Storage:  5x 2TB HDs RAID 5 (8TB total) - http://www.newegg.com/Product/Product.as...6822148910
OS: 120GB SSD (Samsung 850 EVO) - http://www.newegg.com/Product/Product.as...12K2EV4048
Power: 1600W Lepa G1600 Power Supply - http://www.newegg.com/Product/Product.as...6817494006

Total: $3,779

I've also seen epixoip recommend 3 extra fans to go with the CHENBRO case, but I'm not really sure where those should go. 

I appreciate your thoughts &/or suggestions.