How about something like this? Armor Optimizations are Armor Skin II and III. Took COTW to 4 for the extra AC/feat and Cleric at 29 yields 33 CL (Not much is gained between 33 and 36 CL)http://nwn2db.com/build/?261319
Whirlwind/Improved whirlwind aren't very good at high levels. High level mobs are basically high HP damage sponges rather than being high AC tanks. They typically have mid 70s AC while your AB will be in the lower-mid 90s, meaning you'd typically land 4+ attacks per round. Using up a full attack round to hit each surrounding enemy once with whirlwind is usually not worth it. Would skip that.
Spring attack is also utterly useless as you will automatically succeed with tumble checks - it's only use is as a pre-req for weaponmaster.
The plant domain is great if you have 30+ cleric caster levels, as the Barkskin spell translates to +3 AC end game - I took Shadowdancer to cover the missing uncanny dodge, and you can now also do HIPS shadowdancing mid melee with this build.
Adjusted starting stats a bit - you'd need a +12 wis item to cast properly (Look to trade for a +12 Wis girdle of Kleros or a Tormite belt)
I dropped the great strength, quake shock and sweeping strikes feats to trade for Steadfast (don't autofail and die on a 1 fort roll) and Selfconceal V. Also traded quicken (won't use much) for Persistent spell (Divine favor duration is fixed at only 10 rounds otherwise, Weapon of Energy is another good persistable spell, as is Prayer.)
Do note that quite a few of the feats can be found on gear (specifically - Practiced Caster, Extend Spell, Persistent Spell). If you do find gear with those feats, you can replace them with: Holy Warrior (+4 damage), Expert Tactician (+1 hit) and Sweeping Strikes (Extra attack).