My main suggestions in addition to what you’ve got:

• A bralette or two (note that bralettes are a good call as you don’t have to worry too much about sizing, not having breasts - will look more natural on you than a bra without breasts in it)
• A skirt or two (one mini, one midi)
• A garter belt + stockings
• Some more comfortable, bigger panties for long-term wear (ideally ones that fit your whole clitty in them easily)
• A camisole
• A choker/collar

Extra fancy:

• A sundress
• A bodysuit
• A crop top