1） agree with ice watch;) but actually it also depends on whether u r using 讲究 as verb/noun/adjective. need full context to determine the best option.
2） agree with starlight & snowcloud:) Just to add:
需要：need to have, i.e. essential （acts as a Verb; followed by Noun; can also act as a Noun)
须要：must have (is an Auxiliary Verb before proper Verb; cannot be used as a Noun)
Also tone of 须要 is a bit stronger than 需要