Deciding 430exII or 320ex?
I have a few 580EXII's and use Yongnuo's for slaves.
Their latest (I have 2) is essentially a 580EXII - see my comments in the Studio Lightning forum here
What I find VERY useful is it has optical slave modes and audible feedback. These are invaluable for shooting interiors -the trigger is more reliable than using the Canon master/slave system (of course it only useful for manual mode on the slaves)
OH - and you can get one for about $160