I´m personally a huge fan of natural plants.
There are several species that thrive with low light and require no fertilizers or special care whatsoever. The ones mentioned by Ray, elodea, java moss, java fern and anubias do great with low light, and all you have to do is trim them every few months.
Natural plants are a huge help with maintaining water quality. They absorb nutrients, add oxygen to the water, provide a lot of surface area for beneficial bacteria to stablish on, bring a new dimension to the aquarium(because as they grow, the aquarium is constantly changing), and compete with algae. They also acomodate a variety of microinvertebrates that also help controlling water quality.
The downside of course is that you need to syphon out the dead matter that accumulates as parts of the plants decay, but you need to syphon out debris anyway, so it´s not a big deal.
As a plus they can also takeover the function of the filter. A low current filter is of help in an axie tank, but since the species lives in a lake, i think it´s good to avoid currents altogether....
As i said, live plants pretty much do the same job as a filter, without the issue of currents.
I really recomend them. Mind you, it´s not like plastic plants aren´t good...they just don´t have the same advantages as live ones.
It´s all up to you, since all options mentioned work, i´m just letting you know what works for me.