Lately I've built a few rigs with that chip and honestly the 14900K is a literal heater if you dont control the power limits right away. In my experience, you dont need to spend $800 to get stability, but you definitely cant cheap out on the VRMs either. I've tried many boards over the years and for a workstation, stability is basically the only thing that matters... especially when you're rendering for hours. Here are the two I'd actually trust for a deadline:

• MSI MAG Z790 Tomahawk WiFi DDR5 is my top pick for pure value. The power phases are rock solid and MSI's BIOS Lite Load feature makes undervolting a breeze without losing stability. Ngl, it's not the prettiest board but it just works.
• ASUS ROG Strix Z790-E Gaming WiFi II is what I'd go with if you want the best BIOS experience. It has 18+1 power stages which is overkill in a good way for the i9. The VRM heatsinks are huge too. It pushes your $500 limit but the AI features for undervolting save so much time. I'd probably grab the MSI if you want to save some cash for more storage or RAM. The Asus is great but you're paying a bit of a premium for the brand name. Just make sure you update the BIOS first thing to get those new Intel default power profiles... it helps a ton with the stability issues people have been seeing lately.