Do you have 2.5g AGA tank available where you are? Because that would be a great size tank to use. It would give you more water volume and room for plants. For such as small tank look for plants tank stay small or can be trimmed to stay small. Anubias, Crypts, Java Moss, etc are all good low light plants. Substrate is all personal preferrence but Flourite or Eco complete are good plant substrates. I use Flourite and really like it.