Just make a build that will primarily be used for gaming. My budget is 1k-2k with some wiggle room.

First of all, you don't need to select every categories in the custom builder, optical drives, hard drives are rarely seemed in today's gaming pc while mouse/keyboard/antivirus can be purchase separately or even from somewhere else if you need them. Second, I don't know what happen to the heatsink option of the custom builder and where does all the air tower coolers go, but this heatsink is certainly not going to take on the heat that a 10th gen i9 is going to generate. Third, a 75 hz 1080p monitor makes completely no sense for a gaming pc, with that budget you want to look at a high refresh rate 1440p monitor

Given that 12th gen just come out with solid rock high pricing and ddr5 ram kits are merely non existed I'd suggest to go with ryzen platform. For your budget take a look at this:

For the graphics card, unfortunately the newer graphics cards are very limited on stocks. It is going to be any rtx 30 series graphics cards that are in stock in your local microcenter at the pricing you are willing to accept. This build is definitely good for next 3-5 years on gaming, you just probably need to upgrade the graphics cards depends on your final choice on gpu.

You dont need a heatsink/cooler if you are using liquid cooling. You don't need a hard drive when you do have a solid state drive, they both act as storage.