Fluorite is my personal preference. Eco complete is good stuff, but I don't have as good of a growth rate in eco as with fluorite. Laterite is another option as well, and if you have the money, ADA aquasoil is supposed to be really good. 2" is very shallow, and I would recommend an absolute minimum of at least 3" for most plants. With root feeding plants, such as echinodorus species, this should go up to at least 5". Fluorite is a clay based gravel, and will not get sucked up when doing a gravel vacing, but in a planted tank, gravel vacing isn't needed, unless it is sparsely planted.