I don't think the sheen on the paint matters too much, nor the brand. Flat, Satin or Gloss are all gonna look the same on glass pretty much. The amount you'll need also varies by the size tank and how thick the layers are applied. 175 gallon will need a couple of large tubes, maybe more IMHO. I've used whatever craft paint was on sale for dirt cheap at the craft store, I've used stuff from Walmart, even Eggshell wall paint left over from painting a room and it all worked on the glass. I've also alternated colors using blue, then purple, then blue again with interesting results. My artist ex painted a mural on the back glass of my mom's tank using artist acrylic and a couple of artist brushes. The trick on glass is to paint the scene in reverse of the way you'd do it on a canvas with details first and then the background painted last. If you want to do it this way, remember one important detail- the hair dryer is your bestest friend!