wakywolf

thats a sata power cable, look for a female connector coming FROM the power supply that will have a small slit with an L shaped side for you to fit it into. 

One of these...

 

PCPartPicker Part List Type Item Price CPU AMD Ryzen 7 3700X 3.6 GHz 8-Core Processor $324.98 @ Walmart Motherboard Asus PRIME X570-P ATX AM4 Motherboard $149.99 @ Amazon Memory Crucial Ballistix Sport LT 16 GB (2 x 8 GB) DDR4-3200 Memory $64.98 @ Amazon Storage Crucial P1 1 TB M.2-2280 NVME Solid State Drive $99.99 @ B&H Video Card EVGA GeForce RTX 2080 SUPER 8 GB BLACK GAMING Video Card $669.99 @ Newegg Case Fractal Design Meshify C ATX Mid Tower Case $99.98 @ Newegg Power Supply Corsair CX (2017) 550 W 80+ Bronze Certified ATX Power Supply $39.99 @ Newegg Case Fan be quiet! SilentWings 3 PWM 50.5 CFM 120 mm Fan $25.90 @ Amazon   Prices include shipping, taxes, rebates, and discounts     Total (before mail-in rebates) $1525.80   Mail-in rebates -$50.00   Total $1475.80   Generated by PCPartPicker 2020-01-22 16:47 EST-0500   This 2018 super has three display ports, not sure if that's enough

He said AT LEAST $1800.  He's the opposite side, he wants to be able to say how much it cost, so add another $400-$500 to your build. 
 
I advocate a 1440p monitor for the $400 additional.

1. I dont see why you cant afford a 750W PSU
2. SSHDs are a waste of time, their cache size is too small for any use on a platform that can use huge capacity SSDs anyway
3. Big case? Corsair 750D, Fractal Define R6/S2, Lian Li PC-O11 Dynamic XL etc, I dont know what you want from it apart from space
4. Might as well get larger rad when price is not a consideration, 9900k is hot.
5. There's also no motherboard