Sorry about the pics peeps, we had visitors on Saturday and I didn't get anything done. Sunday was a little more productive and I managed to pretty much finish inside the case. It was slow going, though, and I managed to take some pics.
I still have to install the HDDs and connect them, but to save complications/issues, I'll leave that until I've loaded Windows on the M.2 SSD. There's some cabling to do, but I'm going to leave that which was already there to save time. This build has taken more than long enough already and I just want to get it booted.
Anyhow, here's those pics:

The inner workings. As you will see, the ATX power connector is flat and facing right. I've not seen this before, but why not? It is a great idea and makes cabling easier and tidier. Another plus with this board is there are two 20 pin USB 3.1 gen 1 ports, one a centre board on the right, and the other at bottom centre. There is also a USB 3.1 gen 2 front panel connector at centre board on the right, so there's no shortage of high speed data transfer abilities.
The two thicker looking cables at centre case are actually bundles of 6 and 4 SATA cables respectively. I just thought it better to encase them in that stretchy stuff than having 10 loose SATA cables with a couple of ties here and there.

A closer look.

A new shot of the rear showing the IO back panel, which now has the plate built into the motherboard and not fixed to the chassis, which is generally the case with most boards I've seen.
Some of the inner case cabling was in place already, but I see where some of it could be improved so I may yet make some changes.... will provide pics of any alterations.