Black Diamond blasting sand is inert and won't effect pH. It's also coal slag and magnetic so be careful with your magnetic glass scrubbers. The accusations of it causing issues for diggers and/or barbel damage is a disproven myth, it is perfectly safe. Personally, I love the stuff and so do my fish (which include Cories, BGK, Pleco).
Play sand is very fine and can be messy.
All substrates will require root tabs at some point if you plan on growing root feeders (Swords, Crypts, etc).
If you have the funds EcoComplete is the way to go. No rinsing, easy to work with, mixes nicely with sand so you can bring the cost down a bit but keep the mixture above 50/50 (in favor of EC) to keep the benefits of the high CEC.