Planted Tank Obsessed
Join Date: Jan 2012
Location: Millersburg, PA
Sand and root tabs/caps will work just fine! I use pool filter sand (light/white), but others use black sand blasting grit. Both are inexpensive and readily available.
As for the driftwood, you should be able to find pieces online for more... average tank sizes, and then saw it up yourself to fit the tank. You can also take a trip to a local park, river, creek, etc. and look for your own. There are plenty of directions floating around on how to prepare wood that you've found for your tank!
DIY CO2 is FUN! Definitely give it a go!
I can't answer anything else, really, because I'm a beginner myself! I'm sure experts will be along shortly.