Should I Update Bios or Clean Re-Install OS (Win10) First?

Note: Some user complications may occur in the area between the keyboard and the chair...

Hi all, I'm going to be doing a combination Clean Re-install of Windows 10 via USB Flash Drive, as well as updating my bios with the hope of narrowing down and clearing up a number of issues I've been having. The one thing I'm uncertain of is which I should do first? I've seen both tutorials on TH's forums in regards the general steps (and obviously it's not a bad idea to double check and compare with any particulars related to the specific motherboard and manufacturer), which gives me the feeling I should be doing the clean re-install first. However, I have some doubts.
For one thing, I'm very strongly considering swapping out the SSD I'm currently using as my OS/Primary drive for a newly purchased one. For another, I've been having some signal integrity issues with my second newest (very recent) SSD addition, an 850 EVO 500gb I'd intended to use as a games drive. I'm obviously considering the SATA III cable itself is just bad for whatever reason (it has a secure latch, and I'm pretty sure I've already bounced it between a number of differnt 6gb hubs on the mobo). But I also wonder if the bios update might improve some things there.

Sidebar Question: What do people think about the full professional package of CCleaner Professional Plus (paid license for CCleaner Pro, Recuva, Defraggler, and Speccy) and/or HD Sentinel? I currently have CCleaner Pro and was considering doing some sort of upgrade or addition of to it, but I don't have a real sense of certainty in the value. Currently using a free trial version of HD Sentinel, which gave some good info in regards my ssds, etc.

I apologize if this isn't as informative as it could be, I'm bouncing between school and computer issues - plus life in general - so I'm a bit frazzled currently. Can happily answer questions and get further info as needed. Computer specs below.

Full System Specs - homebuilt

OS:
♦ Windows 10 Home 64-bit (free upgrade from Windows 7 Home Premium 64-bit OEM)
CPU:
♦ i5-3570k @ 3.40 GHz (3.8 Turbo)
CPU Fan
♦ COOLER MASTER Hyper 212 EVO RR-212E-20PK-R2 Continuous Direct Contact 120mm Sleeve CPU Cooler Compatible with latest Intel 2011/1366/1155 and AMD FM1/FM2/AM3+
Motherboard
♦ ASUS Maximus V EXTREME Extended ATX Intel Motherboard
RAM
♦ 16 GB of Corsair Dominator Platinum at 1600MHz
PSU
♦ COOLER MASTER RS-A50-SPHA-D3 Silent Pro Hybrid 1050W Intel ATX 12V V2.3 & SSI EPS 12V V2.92
Graphics Card
♦ AMD 7870, 2 GB VRAM (XFX Double D FX-787A-CDBC Radeon HD 7870 GHz Edition Black Edition 2GB 256-bit GDDR5 PCI Express 3.0 x16 HDCP Ready CrossFireX Support Video Card w/ most current driver)
Current* Primary Drive (OS Win10)
♦ (Local Disk ( C: )) - SAMSUNG 830 Series 2.5" 256GB SATA III MLC Internal SSD
NEW (incoming) Primary Drive
♦ SAMSUNG 850 PRO 2.5" 256GB SATA III 3-D Vertical Internal Solid State Drive (SSD)
Secondary Drive
♦ (Games (E)) - SAMSUNG 850 EVO 2.5" 500GB SATA III 3-D Vertical Internal SSD
Tertiary Drive
♦ (in two Volumes (F & G)): Seagate Barracuda 3TB 7200 RPM 64MB Cache SATA 6.0Gb/s 3.5" Internal HDD

Peripherals / Other