No different than any other "Caster biased" Sacred Fist...
Level splits:
M3/C9/SF10/H8 - One spell powers give you CL30 and can pick three more Hierophant abilities. or can grab 3 SP for CL32 which makes you more difficult to dispel with mords.
M5/C9/SF10/H6 - 3 Spell power gives you CL30.
M6/C8/SF10/H6 - Same as above, but CL29. In exchange you get more monk speed, improved knockdown and more fist damage. Credit to Tsidkenu for swaying me to this one being the favorite of the three. CL29 is perfectly fine against greater dispel (only 5%) and what you gain from that extra monk level is significant.
You basically want high WIS for AC and spells. STR can be ~16 - 20, but end on even because you live off of Divine Power. AB will still be fine due to Divine Power, Divine Favor, Bless, Prayer, Aid and in Epic levels Expose Weakness.
Let me know if you want something more specific. I think I still have a few example Grey Orc Sacred Fists collecting dust at NWN2db... I can look for them if you want.
EDIT: Sorry man, long day and didn't fully read to see you posted a build.

So as stated previously your level splits need work, one of the 3 splits I listed above are recommended. You will appreciate more WIS for spells and AC, stopping STR at 20 should be plenty. Personally I would reverse them to go for STR 18 / WIS 26 (24 with Divine Power, 30 WIS with +4 item or Owl's WIS). I also agree that Fiery fist has semi-limited use, though if you have 30 WIS the duration along with 2 uses of Sacred Flames and 6 Monk levels (for example) means you'll have far more uses of applying some fire damage on your attacks. That said, Able Learner would be a boon with this build as you won't have much of an option to rotate levels in order to qualify for Hierophant.
Also, just to make things more difficult for you there is a middle ground... If you go M13/SF10/C7 you have CL19 with level 8 spells and qualify for blazing aura, along with Greater Flurry of Blows and lots of fist damage... So it is not so simple as going for M20 OR going for CL29/30. The middle ground has some interesting things to offer as well, depending on what interests you about SF builds.