But surely, if one cannot justify the extra money, then budget is an issue? To me, "budget is not an issue" means that you may as well go for the latest and greatest.
Anyway, the 5930K is a great CPU for the work you need to do, but expect to pay a big premium over the 4790K and 6700K ($200-$230 USD). Premiere Pro will utilise all of the available CPU threads, so you'll certainly see increased productivity with a 5930K.