I have been thinking about the spell progression as that seems to be the issue.
Thought #1
Reduce all spell levels number of slots per day by one. The level at which new powerful spells are attained, i.e. 1st, 3rd, 5th, etc would thereby be delayed by one level.
The rationale is that these levels have a "dash" and not a "0". Paladin-like spell progression usues the "0" mechanic to allow spells for higher wisdom scores. However clerics do not use this mechanic normally and there is no reason to institute it.
The effect will be like an inverted sorceror progression, i.e. delayed spell levels, full caster power but fewer rather than more spell slots.
Thought #2
As above but institute the "0" mechanic for base spells per day that have reduced from 1. This is clearly more generous as this cleric will have a high enough wisdom to largely ignore this for the early to mid levels.
Domain spells can only exist either way if other like levelled spells are castable (such a word?).
I have never been a big fan of prestige classes and this campain may not go to high levels. My friend does not want to multiclass and I like tinkering with classes,
I just like doing it.
BTW thanks for all the opinions for and against, I was in danger there for a while of making a monster of things. Question is, generous "o" or strict "-"?