
Louise Bishop |

If your focus is on pure Curing and Channeling then go with the Spirit GUide Life Oracle.
If you want to do more with your standard action than Cure or Channel then CLeric is the way to go but not the Healing Domain.
Channeling on a cleric is usually terrible. Only a small handful of Builds (Hangover cleric) benefit from channeling. While the Life Oracle does it so much better due to the CHA focus.

Louise Bishop |

The oracle can handle condition removal too, but he will need to use up a large amount of his spells known leaving him much less useful, when healing isn't what's needed.
You can always ask the group to help float some costs to Scrolls or Pages of Spell Knowledge for the Condition removal. I mean you do get a few via mystery spells so you're not buying all of them. And once Heal comes around most the time you will need to heal condition AND HP.

Mysterious Stranger |

Since this is for an NPC the oracle may be the better choice. If he uses up most of his spells known for condition removal he is less likely to overshadow the PC. Normally having to use up your spells know would be a big deal, but in this case it may actually be a good thing. If the NPC is just there for healing it may be best to limit what he can do to healing.
Without knowing the full circumstances it is hard to say. If the party is a large one but without any healing having a healer who only heals is probably best. If on the other hand the party is small then maybe a more versatile character would be better.

Quandary |

If you want a character with broader utility than healing, Cleric is the way to go, and they have their advantages re: healing and channeling as well.
Oracle's Channel doesn't heal/inflict more damage than a Cleric's, they just get more uses with CHA focus build.
(a Life Oracle who wants to invest in combat stats and/or WIS for Saves is not huge difference vs WIS/CHA focus "caster" Cleric)
Oracles do remove the Cure CL cap, can convert overflow to Temp HPs, and get the Lifelink ability for what that's worth.
On the other hand, Healing Domain Empowers Cures, with Restoration Sub-Domain adding spell-less Condition Removal.
(or Resurrection Sub-Domain replaces Healing's Empower with pseudo-Breath of Life ability)
Cleric's Channel actually CAN be more powerful than Life Oracle's with Sun Domain adding damage + negating Channel Resistance.
(latter likely compensating for any DC advantage of the Oracle, at least if you focus on WIS/CHA caster Cleric build)
Or, of course, choose from any of the other Domains' broad array of powers.
Which in fact can also add major utility to Channel that the Oracle can't match, using Domain Channeling.
Meanwhile the better Fort Save helps keep them alive, and they get deity favored weapon and summons lists etc.
Other than that, I would note Favored Class Bonuses, for Cleric there is +1 CL vs Outsider SR for Human, +1/3/lvl Channel healing/damage for 1/2 Elves, and extra daily usages for Domain Powers for everybody else. Oracle FCB usually offer faster Curse progression or VERY slightly faster progression in a single Revelation (Elf), or Extra (lower level) Spells Known for Humans etc which while nice as Spontaneous Caster isn't big differentiator IMHO.
And of course, Oracles are free agents with no hard correlation between their powers and alignment and religious/social affiliation... While a Cleric will have some relationship with the deity and their church (either affiliated or as rebel), with their Domains restricted based on which deity & church (although Separatist assuages that, if you don't mind one Domain with lesser CL/DC effects). That can definitely be important, depending on your campaign plot and setting.