1- Laterite- red in color, high iron content, works well for a substrate additive but personally I wouldn't use it alone
2- Seachem Flourite- remains my personal favorite substrate, especially the black ones. Also high in iron but more trace content than Laterite, plus has a very high CEC which means it pulls nutrients from the water column and holds them for the plant roots. Should be rinsed well before use.
3- Eco Complete- very similar to Flourite as far as nutrients but grains vary more in size and color. Doesn't need to be rinsed first, the liquid it's packaged in supposedly will help jump-start a tank's cycle (personally I'm skeptical LOL)
4- Tetra complete- I know nothing about.
You probably want about 3" of substrate in the tank. Keep in mind that over time larger grains will migrate to the top and smaller to the bottom, so the sand will end up mixed in and work its way to the bottom. Unless you like the mixed look, I'd skip the sand.