The 4 Power Sand 2- liter Med. and 4 9-liter Aqua Soil would do it. You could also go wit the 6-liter Power Sand Special Med. and add 1 2-liter Power Sand regular Med. to fill it out.
AMAZONIA is not black. It is a nice chocolatey-brown color-- very versatile and easily ADA's best-seller.
The suggestion of the different sized Power Sand granules is based primarily on tank size- namely height- and the effect of the water pressure on the highly pourous granules of Power Sand. You could use large granule in your 80 gallon if you wanted to for some reason, but Med. is recommended.
There is a chart that shows this concept on the website. www.aquariumdesigngroup.com
click on ShopADG- it's on all the POWER SAND product descriptions, just scroll down.