M1 MacBook Air - 8-core GPU version - and FCPX?

As a trainer and consultant, I've seen lots of Macs slow to a crawl editing with one 8GB RAM. Definitely get the 16GB RAM, it'll save you headaches down the road, and help the Mac live a longer useful life. I've been at video editing for over 20 years now in film, television, and corporate work, and I can easily grind an 8GB RAM computer to a crawl easily.

As for GPU cores, yes, FCP, Compressor, Motion all take advantage of GPU, so that one extra core will help. It may not be a monstrous improvement, it'll be a minor improvement, but you'll want all the power you can squeeze out of a laptop eventually.

If you can afford the MBP M1, it'll out perform the Air easily with serious, heavy, professional level jobs.

The M1 chips apparently give phenomenal performance as you have probably seen.

IMHO RAM is very much overrated.

Yes, you need a certain amount but above that the law of diminishing returns kicks in with a vengeance.

In 2017 I bought a 27" Retina iMac with only 8GB of RAM intending to double it as soon as possible but guess what, I discovered that the machine flew with 1080p footage and even now that I occasionally use 4K, the performance is fast.

I frequently have iMovie, FCP, Audacity, Photoshop and other programmes open simultaneously with no problems.

Needless to say, I never bothered getting that extra 8GB.

Of course, it may be that you will be doing more complex projects than mine, utilising multiple tracks of 4K loaded with effects etc. If that's the case you may need more RAM.