Advice on Parts Please :-)

Learner1

I'm working on building my first desktop and would like to go with the i7-12700K CPU bundle deal with the MSI motherboard and G.Skill 16GB RAM.  I have some questions:

I'm not interested in overclocking, and, with no intention of getting a GPU, I've chosen a 500W PSU (Thermaltake Smart Series 500 Watt 80 Plus ATX Non-Modular), as the 80+ Bronze/Gold, higher wattage options seem excessive.  Please advise if this lower wattage isn't wise!

If I decide to upgrade the bundle's 16GB RAM to 32GB, is there a relevant performance difference between having 4x 8GB sticks as opposed to 2x 16GB?

Is the DeepCool AK400 WH Performance CPU Cooler a decent Cooler for this CPU?  Does it come with thermal paste, or do I need to buy a tube separately?

I have some old laptop HDDs that I'd like to install in addition to an M.2 SSD I have—is there anything to be cautious about when putting older drives in a new build?  

If I get a UPS, is the CyberPower Systems Standby Series UPS (SX550G) a sensible choice?

Many thanks for any words of wisdom!

I've chosen plenty of cores/threads for multi-tasking power, but I'd rather not spend more $ than necessary to have parts that work well together.

My usage is mainly:

--a LOT of research, with multiple browser instances, multiple windows, and sometimes tabs into the hundreds  

--some hobby video recording and editing--I've fumbled my way around OBS, Avidemux, and Handbrake

--watching streamed movies/tv/live sports, perhaps more than one stream at a time, while multitasking on research, shopping, etc.

--no gaming or significant upload beyond occasional video conferencing

PowerSpec_KenJ

The 12700K is rated at up to 190W, but can pull up to 300W under boost. This leaves 200W for the rest of the system, which likely won't exceed 50-75W, so the 500W power supply will be more than enough.

The RAM is DDR4, which is mature at this point, so you won't see any speed degradation with four modules vs two. With a lot of browser tabs open at one time, you will need the extra RAM.

The 550VA UPS will work if you just need to save files and shutdown quickly. If you need a bit more time, I would recommend the 650VA version (SX650U).

As for the drives, a typical reliable lifespan of a hard drive is about 5 years. If they are older than that, you may want to replace them or at least make regular backups. If one of the drives (Hard drive or SSD) is going to be your boot drive and you do not wish to reinstall the OS, you may get a blue screen on first boot. This is due to different storage controllers, especially if you run any sort of RAID. You would need to load the driver for the new board to get it working again.

Learner1

Thanks so much!