Question I am trying to build a 2500 USD gaming rig this August. Can someone recommend me the parts?

Well in August Ryzen 3000 will be around and it should bring impressive specs, but for the time being, I would recommend a 9900k+2080ti.
What resolution and hz is your monitor?
Do you just play games or other programs like virtual machines? What games and programs are most common.
 
Well, it hasn't launched so its only rumors right now, but it is expected to be announced next month.
What is known:
We know it will be 7nm and have a big bump in single thread performance. Intel is currently on 14nm and AMD is on 12nm. Ryzen 3000 will work on existing B and X motherboards. New motherboards will support PCIE 4.0.
Rumors say:
At least 12 cores and 24 threads for high-end models. Early rumors said 5ghz, but more recent and likely more accurate rumors say around 4.5ghz, but we don't know if that's base or boost clock.
You don't need to spend $2500 for a pc to run a 60fps 1440p panel, but it will help for future proofing. I wouldn't wait and i would buy something like this for now.
PCPartPicker Part List

Type|Item|Price
:----|:----|:----
CPU | Intel - Core i9-9900K 3.6 GHz 8-Core Processor | $484.99 @ Walmart
CPU Cooler | Corsair - H100i PRO 75 CFM Liquid CPU Cooler | $119.99 @ B&H
Motherboard | Asus - PRIME Z390-A ATX LGA1151 Motherboard | $188.99 @ Amazon
Memory | G.Skill - Ripjaws V 32 GB (2 x 16 GB) DDR4-3000 Memory | $155.98 @ Newegg
Storage | Intel - 660p Series 1 TB M.2-2280 Solid State Drive | $109.89 @ OutletPC
Storage | Hitachi - Ultrastar 7K3000 3 TB 3.5" 7200RPM Internal Hard Drive | $48.49 @ Amazon
Video Card | Gigabyte - GeForce RTX 2080 Ti 11 GB AORUS Video Card | $1249.99 @ Newegg Business
Case | Phanteks - Eclipse P300 Tempered Glass (Black) ATX Mid Tower Case | $59.99 @ Amazon
Power Supply | SeaSonic - FOCUS Gold 750 W 80+ Gold Certified Semi-Modular ATX Power Supply | $89.99 @ Amazon
| Prices include shipping, taxes, rebates, and discounts |
| Total | $2508.30
| Generated by PCPartPicker 2019-05-01 20:23 EDT-0400 |