Various Anubias and Bolbitis Heudelotii will be perfect for your low-light, West African theme. No need to upgrade lights at all as 1 watt/gallon is quite sufficient (provided it's at least 20 gallon). If you're willing to up the lighting a bit, you can add various Aponogetons as well. BTW by choosing theme based on locality, you're restricting yourself quite a bit. I also doubt that your bichir will know the difference between African and Asian plants.
[edited for spelling]