TubbusMaximus

Fair point. It's highly unlikely I will ever have a build that matches the times as I don't like being a first adopter of new tech. Going gen 4 today does have value for my needs. I'm on an OC'd i5 9600k today, with plans to upgrade my board and cpu next Christmas
 
Your help is much appreciated today, thank you!

There should be (in theory) no difference in performance, assuming both are connected directly to the CPU provided PCIe lanes (as opposed to those coming from the chipset, which can bottleneck).
 
However, as is the case with many motherboards, putting something in the second PCIe x16 slot will drop the primary slot to x8. If you have an especially high-end GPU, this can induce another bottleneck.
 
I would recommend just putting on the motherboard, just to save the cost of the adapter and to ensure the best compatibility in BIOS.

Well I would choose a different ssd as its alot more expensive simply because it's a pcie 4.0 drive while your motherboard doesn't support pcie 4.0 so it wouldn't gain any advantage over other pcie 3.0 drives that are a fraction of the price. 

Monitor looks fine, but that is one of the worst product listings ever. They simultaneously refer to it as FHD and 1440p, and then go on to say it's 2560 x 1440 WQHD 2K. FHD is 1080p, and WQHD is 3440x1440p. I'm assuming the actual listed resolution of 2560x1440p is correct, which would make it UHD/2K. Someone needs to go back to school on that one.