I'm unclear as to how damaging breath weapons are resolved. I thought that Dragonfire Adepts would probably be potent as an arcane unit, though I can't figure out if that's a viable option within these constraints. Perhaps you might consider Varags for melee units if you don't have something better in mind.
I don't even know if this will be of any use or not, but...
Templates for use with non-classed units.
[spoiler]Anarchic Creature: LA+5, CR+0(For Creatures of 1-3HD, more if higher) - Planar p.108
Axiomatic Creature: LA+4, CR+0(For Creatures of 1-3HD, more if higher) - Planar p.111
Celestial Creature: LA+2, CR+0(For Creatures of 1-3HD, more if higher) - MM p.31
Fiendish Creature: LA+2, CR+0(For Creatures of 1-3HD, more if higher) - MM p.108
Pseudonatural Creature: LA -, CR+0(For Creatures of 1-3HD, more if higher) - CArc p.160
Revived Fossil: LA -, CR based on base creatures HD (CR1@1HD) - LM p.118
Skeleton: LA -, CR based on base creatures HD (CR1@3HD) - MM p.225
Zombie: LA -, CR based on base creatures HD (CR1@4HD[Troglodytes?]) - MM p.265
Amphibious: LA+0, CR+0 - Storm p.136
Magebred: LA -, CR+0 - EbCS p.295
Spellwarped: LA+3, CR+0(For Creatures of 1-3HD, more if higher) - MM3, p.162[/spoiler]
The Mounts From Beyond Mars
[spoiler]
Magebred Axiomatic Spellwarped Pseudonatural Heavy HorseLarge Outsider (Augmented Animal, Extraplanar)
HD 3d8+15 (28)
Speed 60 ft. (12 squares)
Init: +3
AC 19; touch 12; flat-footed 16
(+3 Dex, -1 Size, +7 Natural)
BAB +2;
Grp +13
Attack Hoof +8 Melee (1d6+7), Smite Chaos +8 Melee (1d6+10)
Full-Attack 2 Hooves +8 Melee (1d6+7) OR Smite Chaos +8 Melee (1d6+10)
Space 10 ft.;
Reach 5 ft.
Special Attacks Smite chaos, true strike
Special Qualities Excellent learner, low-light vision, scent, swift breed, darkvision 60 ft., resistance to acid 5, resistance to cold 5, resistance to electricity 5, resistance to fire 5, resistance to sonic 5, spell resistance 14, linked minds, spell absorption, alternate form
Saves Fort +8 Ref +6 Will +2
Abilities Str 24, Dex 17, Con 21, Int 7, Wis 12, Cha 6
Skills Jump +19, Listen +6, Spot +6
Feats Alertness, Endurance, Run
Environment Lawful Temperate Plains
Organization Domesticated
Challenge Rating 1
Alignment Always Lawful, usually Evil[/spoiler]
The attack bonus might actually be only +2, but I can't find justification for any of the existing horses spontaneously having a -6 misc. attack modifier