IMO your build looks good. I have the following suggestions:
- Cooler - Get 360mm AIO. 13700K draws 250W like 12900K. You can get many videos on how hot 12900K gets. 13900K is worse. Check Lian Li Galahad 360mm, check Gamers Nexus reviews of AIOs. MSI M360 is cheaper.
- UPS - Get a pure sine wave 2kVA inverter ideally with 200Ah battery, check the power output carefully as 1.5kVA inverters can output 1000W+ but might not be enough if you decide to use other home appliances on it as well. Else, get 1.5kVA UPS, APC is the popular choice.
- RAM - Get DDR5 6000MHz CL36 or lower latency, these aren't very expensive now, unless aesthetics are the priority.
Buy Adata Xpg Lancer Rgb 32Gb 6000Mhz Ddr5 CL30 Desktop Ram (AX5U6000C3032G-CLARBK) online at a very low price in India | UDIMM Factor | Limited Lifetime
www.pcstudio.in
- SSD - What capacity? Cost? Avoid 1TB SN850X heatsink because of cost as KC3000 2TB is ~12k now. Also, mobo has heatsink on 3 of its 4 NVMe slots. So heatsink on NVMe is not required. Use the top most NVMe slot first for OS + main usage.
If you get a deal on used 3090 for 60k or so, it will save you a good amount of money. Can consider i9 13900K if you want more cores. Undervolt 13900K or 13700K to reduce power draw, learn it. Not sure how much impact jumping from 3090 to 4090 will make in your usage.