Help me build a mini itx powerful gaming pc

Hello, I recently switched to Mac from a gaming pc (no regrets, heck windows), thinking I'll wait for the Steam machine to come out for gaming, but I'm too impatient, so let's build a pc again I guess. Thanks for your help!

• New build or upgrade?: New build.
• Existing parts/monitors to reuse? (List with models/links): I have a 1440p ultra Wide 32" (34"?) gigabyte monitor, and I need a gpu that can support that because my last gaming pc couldn't at this resolution
• AAA gaming. I basically want to turn this mini itx into a console-like feel. It will replace any of my consoles. I want to play any game at least 90+ fps with my 2K resolution. It needs to be "future proof", so an older gpu/cpu might not be best. I might do 3D CAD in the future since I'll study engineering, so I must not cut on the cpu power.
• 32GB minimum. No external SSDS or what not, just a 2TB nvme is perfectly fine.
• I guess I don't care that much about budget because I know I'll be spending a ton on the gpu and cpu, but feel free to cut in other parts because I don't care about any special features like RGB and stuff. I don't want to over spend for what it is. In the best of worlds, I'd love 2,000$-3,000$ (Canadian).
• Has to be a mini itx (I know it makes it more challenging, but yeah)
• I don't care about appearance anymore, just give me a case that does the job at air flow and all that. I want a functional pc, not a pretty pc. I'd rather have a closed case though, no side panel. I guess white would fit my keyboards better, but whatever haha.