I've done this before.
It can be complicated for having too many choices to pick from. This is where some experience can help.
Some closets seem bright, but get very dark with the dark-finished organizers. Some get too white-on-white; some really are better off with the wire shelving--many need a mix of answers.
One of the best things you can do, before all this starts, is to find a place, and lay out all of a given person's clothes. Organized them by season, buy use, and by how low they hang from a rod (those that go on hangers).
If you already have a dresser, condier what is in that dresser, and what will stay there, before committing to a bunch of shelf units in the closet. Also, behind a closet door, open shelves are actually better than drawers--you get more storage,and you can see your stuff.
That will let you get sorted out before looking at systems. If you have only 2 or 3 long coats, you only need 6" of full-height rod space. Most systems let you "stack" rods, giving a low rod around 42" high, and an upper rod about 84" high. If you have 4 lineal feet of things that will fit that spacing, then, you only need 24" of space to get all that in.
Depending on the height of the closet user, current seasonal things can be hung on an upper or on a lower rod.
Getting every thing out also lets a person spot things like tall boots, which need more space than shoes (and never fit 'standard' shoe racks, either). Hats, scarfs, similar accessories are less-easy to miss this way, too.