Does one NEED floor standing speakers for HT only?


So this was a question that was asked me, I do not know the answer. Lets say some Good quality bookshelfs vs. The same series floor standing. Specifics.....
B&W 805's vs. 804's or 803's. Is it worth the money for the floor standing ones? as long as I have a good sub? I dont know the answer, help?
baranowski
Baranowski, Good sub is expensive (even if you already have it you could sell it). Same go for the stands. Integration of the sub is not always the easiest thing. I decided to settle for floor standers with 30Hz response and no sub. Certain powered subs, allow with microphone, to compensate overall response which might be helpful if you have room issues.
watching movies i would think that the sub would be a must. but what if i had real good fronts like b&w 801 nautilus? how would that even work for home theater? the processor for the surround sound would send only the lows to the .1 correct? this is through the sub out?