If live plants are intended, then start with them and avoid any "cycling" issues. Plants need nitrogen, and they use ammonia/ammonium as their preferred source. So the ammonia produced by fish and bacteria gets grabbed by the plants. Some nitrifying bacteria will also colonize the surfaces, but the plants are fast to grab much of the ammonia, especially if you have faster-growing species of plants. The nice thing about the plants is that when they use the ammonia, they do not produce nitrite, so the second stage of the usual cycle is not present. This is by far the easiest and safest way to start a new tank. And once it is reasonably well planted, you put in a few fish and as I said, there will be no detrimental cycling effect.
On the gravel, small grain works best. Darker or natural colours look better but also settle fish more; all substrates in natural habitats where most of our fish occur is dark, and the fish is darker on the top so that it will be less visible over the substrate when viewed by a predator above. Gravel or sand will work.
The light is important. I wrote a basic intro to a natural planted tank that is stickied at the head of the Aquarium Plants section, "A Basic Approach to the Natural Planted Aquarium," you might want to read through the 4 parts of that series. We also have plants in our profiles, most of the common ones are there, with requirements and care data.