Hi there,
Personally I stick with dmenu, because it's fast and convenient.
I don't really known j4-dmenu-desktop neither what it brings more than others but if you've got difficulties to built it or use it, don't forget there's also xfce4-appfinder if you need to have an overall look of your applications, that's an idea.
I was using it when I started to use i3, but now with time I don't install it anymore, I guess dmenu + shortcuts launchers are just right to me .
This is my font for dmenu: "Source Sans Pro".
I discovered it in the Anex's i3 edition I think. Letters are properly displayed on my monitor, but before I had a good looking with the font called terminus but it's a really different style ^^ more geek I suppose.
Good luck with your config and your ISO also
