[RUABadFish2]

I'm setting up a very small desk Betta bowl (minus the Betta) under a 3W cree XRE. I don't really plan on making many other tanks, so I was wondering if anyone could point me in a good direction to buy very small quantities of driftwood (like, twigs of driftwood) and substrate by the pound? Here's a pic of the "tank" in progress so you can get a good idea of the size I'm talking about:

 

[RUABadFish2]

Most of the research I've done has hyped up the substrate as an important source of nutrients for the plants. Does it really matter as much as they say? If not, I'll just go grab some of the black colored sand they sell at the pet stores and just fert my bowl. Would that be enough to maintain some java moss and some Hemianthus and Pogostemon?