Under eaves storage - shelves or drawers?

[FantasticMrsFoxx]

We currently have open access to the eaves in what will be DD's bedroom in our loft conversion into which we want to install some bespoke storage.
I'd like some hanging space, but then only have space for either open shelves/bookcase OR drawers. Which would be most useful / suitable as she grows older?
(It's not a new conversion - we bought the house with it and are just getting around to sorting this out!)

Drawers will always look tidier. But does she have a lot of books?

Draws do need a certain amount of depth, back to front, whereas shelves only need about 300mm. If you have more depth, and for hanging you need 550mm really, I am assuming you would recess any open shelves. If you have 500mm or so depth, I would favour drawers. Could you not have shelves where the depth decreases?

The joiner has suggested he can build a shelf above the hanging space / drawers which will be a wedge shape in line with the roof but we can make them big enough to take books. Dilemma solved.

Can I ask what is the length you are considering & how much it's costing to build? We want a similar solution but DH thinks its going to be unaffordable. We've just put a row of drawers for now but obviously there is unused space behind them. Thank you!