If you are looking for simple voip solution then you have to trust me.
I have used many in the past but the one I can recommend to others is Voipography with their PBX on the cloud, Your visitors are in direct connection by click2dial, Your dynamic auto attendant in your hand, your whole sale voice termination, and your secured voice telephony , all in one platform, absolutely the best .
You can check them at
www.voipography.com
info@voipography.com