C.O.
Do you live in an HOA? If so - then check what the rules are.
do you want your house to appear taller? then vertical.
if you want it to appear longer - horizontal.
Do you want Hardee Board or vinyl or wood siding??? Guess I would need more information in order to answer your question.
Weather and the elements make a difference as well...high winds and down drafts...can peel off siding from a home...I would think...not sure...I don't live in Tornado Alley.
The siding company that will be installing your siding will have the best knowledge....