For the current character in ToEE the only somehow useful feat I see is Extend Spell and its more expensive variant Persistent Spell. The latter is only useful if Metamagic Song is allowed (see below), and opens up a wide variety of buffing possibilities (which can be widened with a liberal use of Ocular Spell or Reach Spell, if your DM allows that).
The others are either damage-oriented, situative or too expensive.
While normally there are plenty of ways to reduce metamagic costs (elaborated here in great detail), they are all feat-intensive or class abilities, which you will hard time to access with a start of three levels of bard and three feats not related to the task. A single exception to this is Metamagic Song feat, which allows to DMM-like fuel your metamagic by bardic music uses, which is handy, if your DM agrees with round-the-clock buffs.
You might want to take a look at the ways of optimizing bardic music instead, since you do disguise it as a spell-like recitation anyway (I can't help but imagine a rapper magician here).
For the record, how to make Quicken useful for a spontaneous caster:
- Arcane Preparation feat
- Reduce cost to your liking (several more feats)
- Ponder whether it would be cheaper to be immune to daze and use Celerity.