I agree the wood is killer!
Taking your time and going w/ the proper pendants will result in an awesome tank down the road.
You may need to begin on planting the "sparse" side, as the stump is so massive. You will want to avoid "filling up" all the space. But the tank dimensions should allow for some awesome depth. IMO the stump, tho neat, kinda dictates what your planting scheme should be, rather than complementing whatever you wish to do.
I would replace the current gravel with Eco, if for no reason other than it will look more "natural" - complementing the wood.
I have a buddy who has b&w gravel in his hex planted tank. It works for him b/c his home is decorated pretty starkly w/ white walls and a lot of black leather and wood. And his tank is sort of "flashy" instead of natural.
But I don't think that is the look you are seeking.
Keep us apprised.