Amazon swords grow to be more than 2 feet tall and a couple feet wide... don't think that will fit in your bowl unless you plan on a 40G bowl or something. How about one bunch of blyxa japonica as the background? For the foreground.... could be some staurogyne repens or could do DHG 'belem' or HC or marsilea minuta... just some ideas. I'm about to start a shrimp bowl as well and will piggyback on your thread for ideas!
For floaters, you might want to consider red root floaters, frogbit, or mini water lettuce. Duckweed is also a consideration but can get messy.