This was the first PC built by me and I wanted to go all in and water-cool it within my budget constraint of 2000$.I built it with the intention of using it primarily for gaming, and for CAD (since I'm an Engineering student).
For watercooling on a budget I went with the all aluminum EKWB Fluid Gaming A240G kit, that includes a CPU block, GPU block, Reservoir/Pump combo, Tubing, Fittings, Coolant, 2 EK Vardar fans and a 240mm Aluminum Radiator. Initially I planned to buy the 360mm extension for the kit that would give me the extra radiator space for further overclocking within reasonable temps. However, after overclocking my CPU , I was very surprised with the performance of the chip. It did surprisingly well considering it's 240mm radiator space. It kept my i7-8700k @ 5.0GHz at a confortable 60- 65°C and my GTX 1080 @ stock speeds at a confortable 57°C under load. I will say that I do still plan on buying the expansion kit, but I'll take my time and recover for the whole in my pocket this build has created. :D
The i7-8700k was the obvious choice because it offered the best middle ground from two worlds, Gaming and Productivity. Its Multi-Threaded performance is within margin of error of the productivity inclined AMD Ryzen 7 series chips and its single-threaded performance is vastly superior to what any other chip is capable of offering today.
For the motherboard, I had to go with Asus Prime Z370 since it would work perfectly with the black and white theme of the build. Not to mention it's Aura Sync RGB capabilities and the very respectable overclocking performance of the VRM's.
I chose the GTX 1080 as the graphics card because it is the sweet spot for ultrawide 1440p 100hz gaming! It has been delivering on what it promisses!