I would suggest a pair of german blue rams or apistos, some zebra loaches, and a large school of tetras or pencilfish. Put a thin layer of peat underneath the substrate to help lower the pH. I am going to buy a bag of Lesco ProChoice Soilmaster because it is a good plant substrate, and it is much cheaper than the others. But you'd have to look to see if there are any local stores because shipping a 50# bag is pretty expensive. For plants, depending on your lighting, I would suggest some sword plants, anubias, crypts and fast growing stem plants like rotala and green hygro.
7 gallon in the works ~ planted ~ CPO's & Gardneri Killifish