This is kind of a "walk in but then don't move" closet. That's OK - I have one of those too.....mine is a touch wider (5.5'), but shorter. I agree that putting a hanging rack against the long wall will leave you with just under 3' of space between the racks and the wall (with the doorway), but that's still enough to stand there and choose what you're looking for; I know, because I've been doing exactly that for 12 years. However, it means you can't really put any storage furniture along the wall with the doorway.......So now you've got the back wall for hanging racks (you can do multi levels), and a very small amount of depth for shelves or a set of drawers at each short end. If you make the shelves on the short sides too deep (even where it won't bump into the doorway), it will conflict with the hanging clothes - either you won't be able to get to the shelves, or you wont' be able to get to the hanging things. (Of course, you could use a corner under a hanging rack for seasonal storage, only getting in there two or three times a year to switch out swimsuits and sandals for sweaters and thermal underwear.)

You can still get creative with some of the space along the wall with the archway, using it for things that really have no depth to storing them -- a rack for belts or scarves, for instance, or maybe hanging jewelry storage.

Also, remember to think about YOUR (collective) personal clothing storage needs, which aren't the same for everyone. I have very little need for full-length hanging space, for instance, as I wear almost no dresses. That means I can use half-height hanging space, and still have space for drawers and/or shelves beneath them......all my jeans and casual pants hanging over a chest of drawers.