Differences bwteeen megi's kernel e sunxi64

[alpineduck]

I can't answer your question, but at least differences between kernels are unrelated to firmware. Any Linux distribution which supports the built-in wifi chip will come with the same proprietary firmware. Whether you don't want to trust it and prefer using an external USB dongle which doesn't require closed-source firmware is up to you and should be possible no matter the kernel and distribution used.