Full-out cleric specialization isn't a rule I care for, but that being said I agree with Ty 100%. Clerics choose a patron deity, and the nature of that deity influences one's spells and occasionally has a few other quirky effects ... the goddess of death in this game-world's pantheon, for example, is violently opposed to undead (the souls and bodies are hers, as she sees it) and therefore, though she is Neutral (with slight evil tendencies) all her clerics regardless of alignment turn undead as though they were good-aligned clerics.
If more details of the pantheon are needed I can provide them, though admittedly some details are works-in-progress, and I am flexible if someone is interested in a god or goddess that I don't describe.
Also, however, this means that a cleric is not -restricted- to the spells he or she can get, the way a 3E is by choosing specific domains. This allows the gifting of spells based on what the cleric may encounter, and what the god or goddess is willing to grant in response.
Further house-rule (based on a similar rule from 1E) is Divine Intervention, allowing a cleric, once per day, to petition his or her god(dess) for a spell that is really needed right then, even if it wasn't prayed for or granted at the beginning of the day. Of course, the cleric must have an uncast spell/slot that the spell prayed for can replace, or the cleric is SOL.
Gear is purchased based on PHB rates. If you really want something from another source, like UA, or wilderness or dungeoneers survival guide, that is ok too. All characters will start with 120 GP as a tangible benefit of the Royal Commission that brings everyone together into one group. No magical items to begin with, however.
And as far as Monks go, I can see your point about them being an interesting character class, but in honesty place them with barbarians and cavaliers in terms of being classes that don't quite seem to fit .. in my opinion of course.