
Now that you've learned the hard way about the nitrogen cycle and don't want a lot of work, I hope you'll be doing a fish less cycle. No water changes...just feed the tank, test the water and let it do it's thing.
Once it's cycled and add fish, weekly maintenance should be all you need to do.
Fish that don't swim fast or slow? You mean just kind of hang out?
There are several types of tetras that would be nice.
I have neons and serpae, I love them both.
Take a look at some of their profiles:
http://www.fishlore.com/
Good luck.