You could use these, but you lose 2 CHA for it. It's still not a bad option, as you'll get +2 STR and a Natural Weapon from your shifter trait, for example.
Shifter Druid Substitution Levels (RE, p 126): add balance, climb, and jump to class skills
1st level: Beast Spirit (Alertness, Extend Shifting, Reroll Will Saves, +2 STR/DEX/CON), replaces animal companion
4th level: Reckless Nature (+2 initiative checks and reflex saves, -2 to will saves), replaces resist nature's lure
Another option is using these in your build:
Fey Shape (General)
Due to your close blood ties, you may turn yourself into the shape of a fey.
Prerequisites: Fey Blood, wild shape ability (6/day).
Benefit: You may use your wild shape ability to take the shape of a fey creature with which you are familiar. You gain all of the extraordinary and supernatural abilities of the fey, but not the spells or spell-like abilities. You do not gain supernatural abilities that require a specific fey-crafted object or terrain feature (such as a grig's fiddle, a satyr's pipes, or a dryad's tree dependence), and you may only turn into fey whose Hit Dice are no greater than your druid level. You may not change gender as a result of wild shape, so certain single-gender fey (dryads, nymphs, satyrs) will be unavailable as well. Being in fey shape grants a +10 circumstance bonus for Disguise skill checks when pretending to be a fey.
Wow!
Leader of the Pack (General)
Your unique understanding of the effect music has upon animals allows you to inspire your animal friends to greater efficiency.
Prerequisites: Animal companion ability, bardic music ability
Benefit: When you use your bardic music ability to inspire courage, inspire greatness, or inspire heroics in your animal companion, it gains double the normal benefits. For example, a 1st level druid/9th level bard could use inspire courage to grant his animal companion a +4 morale bonus to attack, damage, and saving throws against charm of fear effects, or he could use inspire greatness to grant it +4d10 Hit Dice, a +4 competence bonus to attack and damage, and a +2 competence bonus on attack rolls.
Giving your Animal Companion, +33 Attack, +24 Damage, +24d6 Sonic Damage and +9d10+150 Temp. HP is scary, and yet possible.