normally its best to plant heavily from the start, at least from what i've read. Depending on your scape, it's tough to put a number on how much of what you'll need since they all come in different sized, stems, ect. with the two listed plants, you wont need any root tabs. For the sand, may i suggest moss on rocks. They'll feed from the water column and they're super hardy and grows extremely fast once acclimated.