Ethernet drivers exist in my image. I tested it before I uploaded it. Your image uses a mainline image, and I provided ethernet patches for that in a post above. Apply the patches and enable them in the defconfig and your own kernel should have them.
You set the ethernet driver by doing `make linux-menuconfig`, going to Device Drivers, Network Device Support, Ethernet Driver Support, and selecting "SUNXI Platform Network device drivers", and the three options below that.
The only way I know to add drivers to a linux kernel is to build them when you build the kernel. There is no need to download my github and try it, because I gave you the compiled kernel with the drivers in it. If you meant wifi drivers, then you would download mine and patch the kernel to add the drivers, and select those drivers from the `make linux-menuconfig` command, and build the kernel that way.
When I put the project together initially, I had a working mainline vanilla boot for the nanopi neo, and I modified armbian's sources to create a legacy buildroot image with realtime capabilities for the nanopi neo. Any use outside of that is up to the end user.
I'm not familiar with wireless drivers and I really don't want to spend the time to get them working. The only way I would get them working is if @Igor decided there should be a minimal buildroot image for every board Armbian supports, and I don't think that is likely.
If you can't find your device on your subnet, you can try Wake Me On Lan for windows. It will show you every device your computer can ping. If you use linux, nmap and arp should do just fine.