Cardinals get larger than neons, and I always thought that they would be fine with angels. Glowlight, pristella, flame, black skirt, etc. would work, and as far as I know the rummynose would be fine as well. Keep in mind that rummynose swim almost exclusively in the bottom half of the tank, so if your corys provide you with enough activity at the bottom of your tank you may want to choose a different species. They are very tight schoolers though, and very interesting to watch.