PW Plus III vs. Odins - or else
I would agree with Scratchdisk, the Odins are brilliiant, but its going to be pretty difficult to integrate the Sekonic at this stage.
The PW ControlTL do sound like what you're after, its really just the 580exII thats the main issue there. 430exII are pretty safe, and the 600EX-RT have good reports with the PW as well (although you are doubling up on triggers there).
Have you considered the inexpensive YN-622C in the mean time? -http://flashhavoc.com/yn622c_review/
They are pretty seamless now, though you do need to scroll through a few camera menus to change manual power settings in multiple groups, the Odins are much faster, there but the 622C work fine with a light meter using the test fire button to take readings.