How come you're using spring water? As far as plants go, they would like more nutrients, some of which will be present in tap water, but most likely not in spring water. This would be ideal for you since you don't want to fertilize (which is ok for such a modest objective).
As for plants, Java fern will do fine, but you may not think it's particularly attractive.
If the tank gets sunlight or possibly its own lighted canopy, then Hornwort will be good, and it looks pretty. It's a floating plant though, so don't bother trying to anchor it.
Egeria/Anacharis/Elodea is also an option. It may grow thin or weak in low light, but it's really cheap, so worth a try.
Hygrophila difformis (water wisteria) will grow as well, as long as it gets some sunlight or supplemental light.
All of these plants are undemanding, cheap and readily available. You won't need extra fertilization or CO2. Stock up and see which ones end up doing well.
As for moving, they will be fine. I move my planted 10-gal between school and home, and the plants don't seem to mind, as long as they get plenty of CO2.