If I go with a 25cm cube, here's the piece of wood I'll be working on to use:
(That 2.5gal tank is gearing up to be a moss growth tank - won't be using it for this project)
Rock will be attached to the base, so it emerges from the substrate well.
Some kind of Crypts will be in the background. Either Wendtii or some fancy red/brown ones I've got on-hand already.
Will probably super glue a few patches of Christmas Moss here and there on the wood itself. Nothing major. Maybe some Fissidens but that's spendy.
Plant options for the front half of the tank, depending upon whether or not I go with CO2: Crypt parva, Marsilea minuta, S. repens. If I go M. minuta, I'll aim for a carpet scenario. If I go S. repens, I'll probably have areas of Aquasoil visible and use it as sort of an accent 'hedge', I think.
Other small wood scraps I've got that can be used:
(That 20gal can you see in the shot contains a couple hundred pounds of stone and all kinds of manzanita)
If I'm able to shake this weird Ohio Valley allergy haze today, I may go ahead and order the cube, light fixture and another AC20. Can do it all for under $100. Just can't stomach another Eheim 2211 yet.
Love how no one on TPT ever tells me not to start another tank.