EDIT: if you read the recipe, the author indirectly states that this is 1 lb of sice solids.... whatever that is.
honestly, I'd just get a small amount of liquid rice extract and use that. It sounds like the guys on that forum are advocating using flaked rice, various types of whole rice, sice syrup.
Since you are a beginner, I'd just say use extract. Using other forms of rice (if I am correct) will require a mash so that you don't end up with a bunch of starch in your beer making it super cloudy or gooey.