Your 20 G
You'll get several definitions of "Low tech". For me, low tech means maintaining a tank with just the basics. That includes, standard gravel, an HOB filter, a heater, a florescent light and a few low light plants and no added ferts. A tank that has more "bells and whistles" than this list isn't really low tech.
You have some high end gravel plans and plants, like the Banana lily, that will need stronger light unless you can find a way to float it. I attach it to a small piece of driftwood with a thin rubberband. This gets the leaves close to the light source.
Anyway, a 20G will tank no time to maintain, so don't worry about spending a whole weekend working with it.
"Fear not my child, just change the tank water."