The problem with having a paladin as your healer is that members of the vocation only learn Heal and Midheal (and Kerplunk, but that's only really good once because it drains all your MP). That means that, without support, they will struggle when facing the higher monsters that can deal several hundred points of damage in one turn. That said, paladins have great strength and resilience, not to mention an excellent coup de grâce and abilities such as Kabuff. I'd recommend having both a paladin and a sage or priest. Priests and sages can both use Moreheal and Multiheal, which will be very useful when fighting aforementioned powerful monsters. Also, sages can often deal a lot of damage with their attack spells when they're not busy on healing. Priests can learn Omniheal, whereas Sages can learn Kazing (very useful), and various powerful attack spells.