The only thing paladins need is a mount and they already have the Vorquin dracthyr racial mounts just add some gold recolors to one of them and call it a day. And there is already an armored Vorquin in the game now they could use as a template.
The paladin mounts are often unique. I think something close might be the Vicious war mounts. 
The other good thing about Dracthyr Paladins is they already have wings so when you use avenging wrath you can have some yellow light effects on your wings.