Only a sociopathic munchkin with absolutely no regard for roleplaying would ever create a build that included that much multiclassing.
So it's time for me to get to work, then.
This contains some things that you've already noticed.
Barb 2 (Spirit Lion Totem ACF, Whirling Frenzy ACF, Wolf Totem Alternate Base Class)/Monk 2 (Overpowering Attack Alternate Base Class)/Dungeoncrasher Fighter2
Gets:
Pounce from Spirit Lion Totem ACF
Whirling Frenzy
Improved Trip from using the Wolf Totem alternate base class. (Unearthed Arcana)
Power Attack and Improved Bull Rush from the Overpowering Attack monk variant class. (Unearthed Arcana)
One fighter bonus feat (Snap Kick, anyone?) and the Dungeoncrasher Ability.
Multiclassing like this only really works for melee characters, sadly.