If you are going to do a biotope you would need to adjust your pH to be around that of the area you are trying to create. Best way would be peat in the filter and IAL. You could also get some stratum like Azoo Plant Grower Bed or Fluval's Stratum. Azoo's will be better as it has nutrients in it, you can get it for like $31 on MarineDepot, both will drop the pH with Azoo's lasting longer and being better overall.
I would do some searching on your own and find plants that grow in SouthEast Asia, which will be a bit harder as the most common biotope would be amazon since those plants are widely available.
15 Gallon NPT
1g no tech bowl in the making