Since it's Rogue and they already hired an European & an Aussie it's not to exclue they could hire another player from theses region. There is not much IGL in NA it's the weakness of this region imo.
If either Hiko or vice don't want to IGL they should be replaced, and as for candidates as IGL excluding vice & Hiko in NA we have : ptr, food, SEMPHIS & adreN, those are the only one i could see do the job.
Now internationally : Happy (Already taken apparently), Hobbit, yam, BARBARR, kioShiMa (Not sure he still wants to IGL), TENZKI (Same as kioShiMa), xelos.
But since Happy is going to VITALITY, Hobbit to HellRaisers instead of DeadFox, and im not sure about kioShiMa & TENZKI i would say.
ptr > yam > food > BARBARR > xelos.