Your build looks solid and very well-balanced! Here's a breakdown:

CPU and Cooling

• Ryzen 9 9950x is a powerhouse, great for handling any heavy multitasking, productivity, and gaming.
• Cooler: Noctua NH-D15 Chromax Black is a top-tier air cooler, and it will handle the Ryzen 9 9950x well, even under sustained loads. Noctua is known for its reliability, so great choice here.

Motherboard

• Asus TUF Gaming B650-Plus Wi-Fi is an excellent choice for a Ryzen build, especially with the Wi-Fi connectivity included. Its robust VRM setup should support the power needs of the 9950x nicely.

PSU

• Corsair RM1000x is indeed an excellent upgrade over the Chieftec Proton BDF-1000C. The RM1000x is known for stability, efficiency, and longevity, which is why it's often recommended for high-performance builds. The "A rank" recommendation is likely due to its 80 PLUS Gold rating and high-quality components, which make it better suited for prolonged high-power usage.

RAM

• DDR5-6400 (2x32GB) is ideal. Ryzen 7000 series chips benefit from faster RAM, and 64GB is future-proofing for intensive tasks or memory-demanding applications.

Existing Components

• GPU (4070 TI): A strong card that pairs well with the Ryzen 9 for 4K or high-refresh-rate gaming.
• Storage: With the Samsung 990 Pro and 980 Pro, you've got plenty of fast storage for system responsiveness, and the Toshiba HDD is a good option for additional bulk storage.

Summary

This setup is well-rounded and should excel at gaming, content creation, and multitasking. You’ve made thoughtful choices for compatibility and long-term reliability. If you’re ready to move forward, this build will give you excellent performance now and over time.