You could prob. get glosso from Aquatic Plant Central in the FS section, many people there, S. repens isn't a fast grower so it would take a while for it to carpet (up to you on fast or not). Also it wouldn't be as thick and profound as other carpets, reason I picked glosso is for the dark green coloration to contrast against the right focal point at 1:30pm to the right of the tank
He only listed glosso as the only true carpeting plant in his sketch. Pearlweed is tech. not a carpeting plant, and is generally used as background plant in aquascapes