There are a number of cereals that are vegan, low in fat, and high in fiber. Here's a few that I know of:
Kelloggs All Bran
Giant Bran Flakes
Cheerios - plain and whole grain
Veganic ancient flakes
Engine 2 Cereals
Kashi Corn Cereal or Whole Wheat Biscuits
The nondairy milk choice is up to you and what you like! Almond milk works well, but so do rice, soy, and flax milk!
Hope that helps!
Maggie Neola, RD