If you are persistifying Divine Power, you might as well take
Cloistered Cleric instead of standard cleric, for the extra knowledge domain, some additional skill points and the free sweet, sweet Knowledge Devotion (Feat from Complete Champion, clerics can get it in exchange for the granted power of the knowledge domain). In fact, you could take it even if you don't want to use persistent divine power at all.
By the way, Travel Devotion (Complete Champion) is pretty good for any character favoring full attacks, and, again, you can get it for free in exchange for the travel domain granted power.
Feats:
3: Combat Casting
6: Persist Spell
9: DMM: Persist Spell
12:
15:
18:
Which feats should I take? Extra Turning till the end, or also something else?
Deppends. Are nightsticks available? Do they stack? If both answers are yes, you are golden without any Extra Turning. Anyway, you can cover most attempts with just one Extra Turning and items, though more persisted spells are always welcomed. If you want to use Travel Devotion and Nightsticks aren't allowed, some more Extra Turnings are great.
If you are using the Embrace/Shun shuffle, then you have a lot of feats to your disposition. You can pretty much take all you want and still get as many Extra turnings as you would want.
I'd say that the number of Extra Turnings to take should be something along these lines:
-Nightsticks allowed and stackable? 0 Extra Turning.
-Nightsticks disallowed and Embrace/Shun allowed? Every feat once you've got the ones you want, so about 6 or so.
-Nightsticks disallowed and Embrace/Shun disallowed? 1 or 2. Maybe 3.
As for the feats... At least, I'd take the following ones:
-Combat Casting (Duh!)
-Extend Spell (Duh, duh!)
-Persistent Spell (Duh dah!)
-DMM: Persistent Spell (Dubi dubi duh!)
-Practiced Spellcaster: always lovely for increased spell effects and increased spell duration.
-Improved Natural Attack and/or Superior Unarmed Strike. Greater Mighty Wallop affects unarmed strikes, and with Righteous Might you'll be throwing more damage dices for a single fist that the standard rogue with a full round sneak attacking. Well, this is a bit of an overexageration, but not by too much. You need a sorcerer/wizard to cast it for you, though. Magic domain can be interesting just to be able to use an Eternal Wand of Greater Mighty Wallop, if you don't have an arcane caster in your group