Need an idea of budget.
You could spend a grand on PWs and 580 guns and still not get a reliable solution if you're not careful (PW interference problem - see website). PW and 430EXII guns is the only guaranteed safe option. Or Radio Poppers maybe.
Maybe you could get E-TTL using a 10m extension lead. Is that practical?
On the other hand, if you go manual with Yongnuo RF-602 triggers, you could use any old guns and have the whole thing sorted for a ton, guns and all.
Edit: let's cut to the chase. Stick your 580 on the camera and use that to trigger slave guns in E-TTL. Nissins are good and quite powerful. Or Yongnuos are cheap. Canons are best. If you're close, that should work.
If you're not close, or the ambient is too bright for reliable triggering, then plug the 580 on to a 10m cord so that it's master signal can be fired close to the slaves, even if the camera is a way off on the other end of the cord.
If the cord option isn't on, or you have other triggering problems, switch to manual with RF-602 radio triggers.
Or. Throw money at Pocket Wizards/Radio Poppers.