if you use an air filter, id switch it off while the pair are spawning, you dont want any eggs being accidentily sucked in. then ajust the airflow (if your pump isnt adjustable, you can get a valve with a tap on it to adjust it) so its just a couple of bubbles a second and leave it that way unil the fry are free swimming, then you can up the airflow a little bit.
as for floating plants, most lfs dont seem to carry them, but most lfs will have bunches of "hygrophilia difformis" a winderful, bushy plant that will sprawl out underneath the surface and grows thick and fast! it does prefer to root down, but it dont need to.
do have everything else prepared? live food cultures(or betta starter if your using it)? jars/barracks to sepperate the young males? homes for the babies, i notice the pair is VT and you will struggle to sell alot of them if you have a big brood, and pet stores wont always take them.