You can always order them - though some online people will not send them in cold weather, depending where you are that is and how long it takes to get to you. I bought my Java Fern online... I want to get in some moss balls next.
Ask Petsmart if they are willing to order in specific plants for you. And make sure you see the plants, see the fish, etc, in that tank for how healthy they are!
I was upset when the store gave me a floating plant that had black hair algae which endangered my female bettas (got caught by their gills!!) and weighed the poor plant down - and looked ugly.