Once you get good at honing the 4k/8k will be all you really need (though not all you really want :-). But while you're learning that paddle strop is an awfully handy crutch because its so easy to get good results. So get the paddle and use it to keep your razors shaving sharp, but keep banging away on the Norton because it'll pay off in the end.

Lap your norton every 30-60 mins of use; those things wear quickly and you want your stone as flat as possible for the best edge.