With those fixtures and 6500K lamps (the stock lamps probably aren't enough), you can grow most low-light plants. Water Sprite is your first choice in this situation- get the functional stuff going first, decorate second. But before we change your lamps, what does it say on the bulb? If its not 6500K or close, its pretty inexpensive to grab some 6500K s from a big chain hardware store like Lowe's or Home Depot.
Its hard to tell from the pix, and I'm def not the best plant IDer... but it looks like maybe 2 Italian Val (vallisneria spiralis) (but possibly sag or even mondo grass) and some kind of sword? If you post close ups, someone can help you ID them. What store did you get them from? Were the little grassy plants sold in tubes from a display rack? Or did the plants come from an aquarium? But, whatever they are, it isn't enough to put a dent in your cycle. Floaters are the best for this- either true floating plants or stem plants that are left to float. The idea is to get a plant that's not rooted in the substrate (and not a root-feeder), and is very quick growing, so that it will suck up ammonia, etc, from the water. The quicker it grows, the quicker it sucks up the bad juju.
The two angels may be a problem. Scalare Angelfish do best in either a breeding pair or in groups of 5 or more. You can click the shaded name to find out why, and more.
You're livebearers require harder, basic water and your tetras/Angels require softer, acidic water. So there's some discrepancy there. Do you know your parameters?
At this point you should be testing at least every day. With your water quality now (all three values being too high), I would test after a 50% change to see if you need another 50% WC back to back. You have a lot of stock in a new tank, and its going to be hard work to get your fish through this. I'm glad you got a Python water changer!