your filters wont suck up the sand. only time you need to worry is if you stir the sand up heaps just turn your filters off for a few mins till it settles. only one problem i had is under my spray bar i had to put a few rocks to stop the sand getting creaters in it. plecos love sand to!
I let the fish I'm keeping show me the direction to go on sand or gravel.
what fish are you planning on getting and will the tank be planted