Hellknight / Stalwart Defender cohort advice.

[bigrig107]

Looking for some advice on my Cheliaxian nobles' Hellknight Cohort.

Level 12, stats start at 10, with 15 points on a 1-to-1 basis.
16,350 gp.

I figured the Hellknight prestige class (the martial one) is obligatory, so no taking that out.
And I'd like to include at least 6 levels of Hellknight, and one level of Stalwart Defender, for the defensive abilities.

Thinking fighter, with phalanx fighter to use a reach weapon, and Shield Slam to get enemies out of his 5 foot reach, and away from his lord.

Now, the question.
Feats, equipment, and the exact levels are what I need advice on.

Any help is appreciated.

[The Morphling]

Greater Bull Rush on that shield slam, so that his lord gets an AoO on the impudent filth that dared approach.

Standstill to keep such swine from approaching his lord.

Trip-based feats too, to knock the knees out from unwashed rabble who aren't properly kneeling.