Please help me with my Half-Celestial Fighter

[Bolber]

My human fighter is Level 3 and he found a really awesome blade(+2 Merciful longsword of Heavenly Burst which is called Sune's Present[the blade of love and peace]). At level 4 i wanted to take weapon spezialisation(longsword). But with that blade i'm not sure if there is a better feat for that level.

The problem is that the other characters in my gaming group have relatively poor ACs. The Monk has an AC of 15 or 16 which is ok i think. But the elven wizard has an AC of 11 and the human druid has an AC of 10. The druid is going to have Vow of Poverty at level 5 but we're using the slow progression for EXP and he offered his armor and his weapon to Silvanus the last session. The druid is going to be a master of many forms at level 7 i think.

I want my character to be able to defend the druid and the wizard. Can you help me with the feats. I think i am allowed to use the APG. I don't know when i will acquire the half-celestial template. Maybe in a few sessions. Although i don't know if the DM will alter the template.
If we're using the normal template i will give the +4s to Str, Wis and Cha.

Any advice on this would be appreciated.

HP: 26
AC: 21(+6 Chainmail, +2 Dex, +2 Shield, +1 Dodge)

Stats
Str: 16(+2 racial) [20 template]
Dex: 14 [16 template]
Con: 13 [15 template]
Int: 14 [16 template]
Wis: 12 [16 template]
Cha: 10 [14 template]

Feats:
Dodge, Combat Expertise, Iron Will, Weapon Focus(longsword), Power Attack

[Tursic]

The feat saving sheild would let you give a +2 boost to AC.

I would say go with body guard but you do not have combat reflexes. At level six you could pick up swift aid. That would let you give as much as a 4 point boost to AC.

[Bolber]

Thanks for your advice. I went oldschool with weapon specialization for the damage for now. With no spells left and everybody wounded we encountered a dire boar. With this in mind i decided i want to be able to dish out more damage.

The last two sessions were great. I forgot to tell that i have Sacred Touch as character trait. I managed to use it twice on the monk who was near death.

The druid is going to be a MOMF at level 5.

Saving shield sounds great but maybe i am going for "In Harm's way". I am also considering to take Step up at level 5 to be a major threat to spellcasters thus being a target which they can't ignore. I think we will meet Spellcasters soon.

The funny thing is that the monk was below zero about five times now and no one else.^^

HP: 38
AC: 21(+6 Chainmail, +2 Dex, +2 Shield, +1 Dodge)

Stats
Str: 16
Dex: 14
Con: 14
Int: 14
Wis: 12
Cha: 10

Feats:
Dodge, Combat Expertise, Iron Will, Weapon Focus(longsword), Power Attack, Weapon Specialization(longsword)