If push comes to shove, u'd be our reference for the same. All u'll need are the 4 SIM cards + 1 RUIM card and some fair amount of credit :)
Orange guys claim this:
I've been using their voip service to call Europe since when they launched CDMA network. The rates have at times (most?) been lower than indicated. Unless something has drastically changed, they have the best VOIP rates compared to competition.
FYI : To use VOIP on Safcom, prefix the numbers with 888, for the same on Zain, use 123.
We now have Izzytalk from KDN. You may be interested to sample that too.