Bard may not be a bad way to go. Your group is lacking a Utility Caster, and most of the Bardic Music powers are group friendly.
A 1st level bard with a master work horn is doing +3/+3 with Inspire Courage which is a substantial boost.
I would chose the Bard Alternate class feature from Complete Mage called Spellbreaker Song. Instead of the normal Countersong power of the bard, you can give a 20% disruption chance to any enemy spellcasters with in 30' for up to 3 rounds.
Very useful.
I would also, when you qualify, chose the Requiem feat from Liber Mortis. This feat lets your mind-affecting bardic music feats effect undead, albeit at half duration. This still should be enough time to get a suggestion off. You might consider asking your DM if you can respec your skills, Perform is a class skill for Rogue so you could if you respec take Requiem as your next Feat.
Being a Bard also opens the way for a lot of very interesting PrCs.
If you need to be a more front line fighter, you can always take the Warsinger Prc,(Complete Warrior, full bab, d8 hp, martial weapons and some pretty cool songs). If your group needs more spell power, Lyric Thautamage (Complete Mage), or Sublime Cord (Complete Arcane) will do the deal.
Moreover, a Bards spell list, especially if you have access to Spell Compendium has some gems on it. A Summon Monster spell configured to summon multiple creatures from a lower spell list coupled with Rage would be a good way to Zorg the enemy, and the Rage spell would be a good way to influence your cowardly Ranger to Role play attacking. It also gives you access to the Arcane Strike feat, which lets you expend a spell to do extra damage.
Your UMD skill will be maxed out, so even with randomly generated loot, you should still be able to do something and you can be a reserve healer.
Undead Bane is obviously a prime choice for weapon enhancement, but do not neglect Spell Storing. In an Undead heavy campaign having a Cure Moderate or Cure Serious wounds in a weapon is pretty good, hurt the undead, or make a subdual damage attack against a friend to heal them.