I've used gravel with Flourite, Flourite sand, pool filter sand, gravel, and play sand. Only the tank with the Flourite sand would have been considered "high tech." It worked well; I kept dwarf cories and anchor cats (whatever their scientific name is these days) at different times on it and they all did great. Heck, the cory cats were just beginning to regularly spawn when I had to tear it down...
All that to say, I think you would be just fine with just about any of the common options you choose. If you feel like going all crazy on substrate (for whatever reason..), I have a thing of ADA Amazonia 2 sand in an unopened bag somewhere. I was going to throw it in a nano tank that never happened.... PM me if that is something you are interested in. If not, just pick a substrate you like with your inhabitants in mind, rinse it, and voila!