The "output" watts is a rough equivalent of light output, NOT draw,. so that number is meaningless as far as circuitry goes.
Also, a continuous load circuit is not one where the load may possibly be on for three hours or more. It is one where the load is expected to be on for three hours or more. If it were the form,er then every circuit would be continuous.
That said, a lighting circuit in a horse barn may very well be considered a continuous load, so wiring it that way would never be a bad thing. Considering the low wattages involved here I don't think it is a big deal either.