OK first of all you've got to understand that ants need to forage. In other words: They must be able to leave their nest and search for food for their colony. This behaviour is completely naturally. Therefore it's necessary to offer them a possibility to leave their nest in order to follow their natural needs. If you offer food, for instance a fly, directly in their nest it will be considered to be an intruder. The result: The colony will be alarmed and some kind of "flushed".
A vertical ant farm and an arena is one possibility to make ants foraging. But this is only one of many options.
If you're interested to keep a little colony you can also use a formicarium, I posted in the link before. The antstore offers a lot of options. Have a look and take your time.

I never kept the two species you're talking about. If you want really good information you should search the forum (respectively the www) for it. Many ant keeper write down their experiences in special threads. So keep your eyes open!
Referring to your question "how long you can make the ants live": I think you're talking about the possible age a colony can reach. Well you have to be aware that the queen is the heart of a colony. If she dies the colony will die sooner or later, too. This is because the queen is the only one who produces
fertilised eggs. New workers develop from these eggs. The queen of Lasius niger can reach an age of up to twenty years. Consequently the colony can get this age, too. Do you understand what I mean? Therefore: If you keep a colony right and healthy you will have a lot of fun for many years.
I hope these information were helpful. Feel free to ask, if you've got any more problems. We're here to help.
Regards
Scooby