The SRD has a cleric variant. It is in the spoiler below.
The cloistered cleric spends more time than other clerics in study and prayer and less in martial training. He gives up some of the cleric's combat prowess in exchange for greater skill access and a wider range of spells devoted to knowledge (and the protection of knowledge).
Most cloistered clerics are nonchaotic, since they believe that a disciplined lifestyle lends itself better to learning.
Hit Die
The cloistered cleric uses a d6 for his Hit Die (and has hit points at 1st level equal to 6 + Con modifier).
Base Attack Bonus
The cloistered cleric's lack of martial training means that he uses the poor base attack bonus.
Class Skills
The cloistered cleric's class skill list includes Decipher Script, Speak Language, and all Knowledge skills (from the Knowledge domain, see below). The cloistered cleric gains skill points per level equal to 6 + Int modifier (and has this number x4 at 1st level).
Class Features
The cloistered cleric has all the standard cleric class features, except as noted below.
Weapon and Armor Proficiency
Cloistered clerics are proficient with simple weapons and with light armor.
Lore (Ex)
Thanks to long hours of study, a cloistered cleric has a wide range of stray knowledge. This ability is identical to the bard's bardic knowledge class feature, using the cloistered cleric's class level in place of the bard level.
Deity, Domains, and Domain Spells
Most cloistered clerics worship deities associated with knowledge and learning.
In addition to any domains selected from his deity's list, a cloistered cleric automatically gains the Knowledge domain as a bonus domain (even if the Knowledge domain is not normally available to clerics of that deity). He gains the Knowledge domain granted power and may select his bonus domain spell from the Knowledge domain or from one of his two regular domains.
Spellcasting
Add the following spells to the cloistered cleric's class spell list: 0—message; 1st—erase, identify, unseen servant; 2nd—fox's cunning; 3rd—illusory script, secret page, tongues (reduced from 4th level); 4th—detect scrying; 6th—analyze dweomer; 7th—sequester; 9th—vision.
It is in the SRD. It allows people to play skilled clerics, without rejigging the whole skill system. More on this later.
The Pathfinder Chronicles campaign guide has a cleric variant. It allowed clerics to sacrifice domain powers, in exchange for fighter BAB and d10 hit die.
A sidebar with these class variants would open up the cleric to new interpretations, without changing the base class further.
[spoiler]
I think the Pathfinder "core" book will be big enough as it is, but I'm 200% behind publishing a Pathfinder "options" book similar to Unearthed Arcana.
I love base clerics and love the Cloistered Cleric as well. I think cloistered cleric would be a wounderful variant to add. It fits many peoples visions of divine casters and character concepts.
I agree. The cloistered cleric fits the archetype of the (non-combat westerner) monk and nuns that occupy a big place in anything middle/dark-ages. Supplements would be a good place for such a variant.