Custom Villagers Mod 1.7.10, 1.7.2 allows you to create custom villagers, with custom textures and custom trades.
This mod also allows you to override vanilla villagers with your own (EG. Replace all priests with your own custom priest). The trades are also randomised, so they will "never" unlock in the same order. You can create as many custom villagers with as many custom trades as you need through the config files.