I use Jamba Setup is pretty straight forward then,
make a macro to,
/Assist focus

or

/assist "insert main's name"

i bind this to "H"

then go into your interface menu, then keybindings, then under targeting there is an option to interact with target,

i bind this to Shift + H

so i walk up to the quest giver target him on main, push H (all slaves target), push Shift + H, everyone opens up Dialog box
from there Jamba will do the rest and replicate your selections on slaves..

Hope that helps i only just set this up on mine tonight im liking it alot
can also use the same combo to loot mobs as well..