nah. i prob wouldnt suggest co2
for you. if you up your lighting or get more serious into plants, then maybe.
jungle vals will get way to big for your tank. i wouldnt do it personally.
some good low light plants would be anacharis, java fern, anubias, crypts, hornwort. take a look at the low light (most medium low will work too)plants at this site. PlantGeek.net - Plant Guide