Best XCOM 2 conversion mods that replace both XCOM soldiers and the aliens?

I'm looking for high quality conversion mods for Xcom 2 that significantly change the theme of the game; ideally replacing both the XCOM soldiers and the alien/enemy factions.

My priorities are quality and stability. I'd prefer something polished enough to play through a full campaign without constantly dealing with crashes, broken enemies, or major compatibility issues.

I played the campaign a few times years ago and I would like to add some flavor. I’ve searched online but a lot of these conversions seem to be split across multiple separate mods and files so it’s been a little confusing figuring out which ones I actually need for the full experience.

What are the best conversions or combinations of mods you've actually played and would recommend? Feel free to rank the ones you tried!

Thanks for taking the time