For more opaque water-based paint, you can try gouache, or simply watercolor with just white gouache. I rather like the latter; it's an easier transition for me since I'm more familiar with watercolors, but occasionally want some opaqueness in there. Either way, all really fun to experiment with!
Hey there, Sure, if you're just creating it for personal use and/or to learn (ie: not for profit/commercial). Feel free to post it up but please be sure to link back to the original with proper crediting. Thank you for asking in advance! (=