Having tried several fighter / mage types I must say that you would be better off with going wiz palemaster 12 + 6lvls of either ranger or fighter + 2 levels of monk or rogue (Kensai I or Tempest I depending if you rather TWF or THF)
WIZ 12 and palemaster just gives so much to these kind of characters. (was even better before they moved lich form to wiz 18)
In form you get 100% fortification (huge), immunity to poison & disease (nice). Self healing. You are also immune to most stuns and neg. levels. Wraith form also gives +25% miss chance to opponents that stacks with blur and displacement. (and featherfall)
If you are going for this kind of build dump INT just high enough you can cast the spells you get and put level ups into STR. You also need good CON.
Bard is a good choise with warchanter. Look up artificer - it might also be almost exactly what you want. Even though it seems like it is geared towards xbows it works quite decently with bastard sword with THF feats as well.
I dont want to be mean but I would caution against going with wiz5 or 6. You will end up feeling like a c-class-citizen at higher levels.