Sapphire Heirarch: Drop BAB, drop Fort, d6. Get casting + meldshaping progression. Think entry can be done as early as 3, but I barely know this book. Gains DR and fortification as well. Not entirely sure about the value of this; so someone has to help me on this one.
Gladly:
[spoiler]And now we move into the dual-advancement classes. At a glance, this PrC is a huge downgrade for a Cleric. d6 HD, poor BAB, one good save. But the truth is, it is a very tricky little class to have. Both Totemist/Ur-Priest and Cleric/Incarnate can enter this class with little effort. So, let's have a look.
Entry Requirements: 4 ranks in two skills, able to shape three melds, and able to cast 2nd level Divine spells (and access to the Law domain), with an Essentia Pool of three. The alignment restriction should actually read Any Lawful. But that is more or less irrelevant. The Lawful restriction means Incarnate/Ur-Priest doesn't work. But Totemist/Ur-Priest does. Good entry is any combo of Cleric and Incarnate that totals 10 levels (Cleric 9/Incarnate 1 for those who want 9th level spells), and Totemist 4 with either Binder 2, Hexblade 2, or Knight 2 with the Educated feat, and Ur-Priest 3/Contemplative 1.
Consultation: 3/level is nice, but the fact that you still pay the XP cost hurts it. Commune is a decent SLA to have, but really, this is mostly worthless. Still, not red.
Smite Chaos: Because it only does class level in extra damage, and relies on melee combat with a dual-advancement PrC, this ability is next to worthless. Still, some like it.
Favored of the Eidolon: The bonus to saves is limited, situational, and minor. But it is a bonus to saves against Transmutation effects. Meh.
DR: Adamantine is common, and it is so weak it almost isn't worth a damn thing.
Sapphire Body: Now we are talking! This is nice to have, and it is Ex to boot!
Timeless Body: And?
Looking at it, this PrC leaves a lot to be desired. But the entry requirements are so easy, it is laughable. Divine Power more than covers your lowly BAB. I'd say the Totemist route is the most potent, as their Meldshaping isn't dependent on too much Essentia or Chakra Binds other than the Totem bind. Too bad you have to spend feats to get new Chakras to bind to. Oh well, a deal is a freaking deal, and the Incarnum domain is wickedly good for any Meldshaper. If you focus solely on the Meldshaping, it is decent. But if you focus on your spellcasting, and use it like a Gish class, then you can do some real damage. Watch out for it.[/spoiler]
As I said, it's laughably easy to enter (you don't even need to dip a level, but that's feat intensive). Focus heavily on your Cleric side, and use the occasional spell slot to compensate for the lack of Chakra Binds. Wands work well for that purpose. If you are looking for more buffs for combat purposes, this is a solid option.