Best Macbook configuration for video conferencing

The M series Macs utilize memory in a completely different manner than Intel Macs. It's not really possible to draw a direct comparison between them, but an M series Mac uses RAM much more efficiently. Whereas your present Mac might be performance-limited with 8 GB, the M series might not be.

More is always better, but...

Would more RAM help (as one Apple guy suggested)?

It's very easy to determine if your present Mac's performance is being limited by available memory. Please read Check if your Mac needs more RAM in Activity Monitor - Apple Support. If the "Memory Pressure" graph is frequently "red" your Mac would benefit from additional memory. If not, it won't. It's that simple.

I was never impressed with the Intel i5 CPUs. The M2 is certain to run rings around it. I cannot guaranteed it but I am nearly certain you will find its exhaust fan will not be objectionably loud given similar apps used in the way you have been accustomed to using them.

Personal recommendation: consider the length of time you want your Mac to remain in service (seven years is reasonable), consider what you are likely to use it for during that time (bearing in mind things will happen in the next several years that no one can possibly predict), estimate the configuration appropriate for those needs... and then double it.

If you are only going to keep your Mac for two or three years, then it doesn't really matter, does it?

16 GB memory is a good choice.

As for storage... it's hard to say, but the minimum available configuration (whatever that happens to be) is certain to be insufficient. To estimate how much you may need, determine how much you are using at present (use About This Mac > Storage), and double it. That result is the minimum you should consider. It takes into account how much storage you have been using and allows for a sufficient amount of expansion.

iCloud is fine but its best most useful feature is the availability of files and documents across all your Apple devices, however many you may have, and wherever you may be. Don't think of iCloud Drive in terms of it being available as "extra" storage. Besides, it's only 5 GB, unless you want to pay for more — forever.

.. but having said that .. I never actually restored a backup from it in the X years it was operational. Perhaps it was just a peace-of-mind thing).

That's usually the way it is 🙂