Which aquarium plants are the best?

Red Ludwigia ~could~ work, but you may lose a bit of the red color. I would entirely avoid the Microsword and "Frill Plant" (which isn't aquatic). Moneywort is another good choice, and will make an interesting contrast to the Dwarf Hairgr you have on the way. Cryptocoryne wendtii 'red' or a Tiger Lotus would be PERFECT choices for some red in the tank, even in fairly low lighting conditions. For a dark green, I like Anubias, and for a very light, delicate looking plant, Water Sprite is great... not to mention it grows VERY fast and will keep algae at bay.