Since you take the door cards off anyway, and in both cases you'd have to either butcher the old speakers to be used as speaker rings for the new ones or buy new speaker rings and have to feed the speaker wire into the door harness loom, it's only a difference of 5 mins to fit the tweeters of the components into the OEM location.
Comes down to personal preference.
I got comps up front and coaxials in the rear, bazooka tube in place of the OEM sub, all powered by an Alpine PDX-5 amp
This is what I did : http://www.350z-uk.com/topic/73153-mould-on-speakers/