simple 2 panel interior door. with a modern styled home I think either a 2 panel door or a flush door looks best, though in a pinch there are some great 5 - 6 panel doors that could work as well. but for me it's always best to keep it simple.
Making your own fitted wardrobe or built-in cupboard allows you the freedom to choose a design and customise the storage to suit your needs. You can also choose the material for making your fitted wardrobe or built-in cupboard, rather than have to settle for melamine or laminated chipboard.