From what info you gave us, I feel like you’re less concerned about what the specs bring bar their abilities to self-sustain themselves. So i’ll stick there:
Warrior does not really have any issue soloing world content and old content. Yes, you’ll have gear issues at the beginning but what class generally doesn’t? suffice to say, Prot warrior does indeed have survivability issues but only because they don’t have a stable healing spell. They have that heal-on-kill mechanic, which works in about anything as I understand. It’s not much, but often it’s all you need.
Simply be assured that you won’t got wrong with picking Warrior. Just that you might need a little leg up in purples and leggo first.
As for DH, seeing as it is Transmog options you had outlined, they generally do not have ‘that’ much of a lacking library if you look past the sets. They can still use recolours and being a fan of generally not using 100% sets across my characters and rather making combinations, you’ll soon find out that you’ll have a plethora of choice available.