Create a secure voip softswitch gui

We want to create our own softswitch with billing system instead of renting one. So we want someone who had strong knowledge in this field who can create for us a rigid gui similar to ixc features.
And that has the feature to run fake rbt if needed and to check the tcp dump, to change the dial plans end codes like 480 and 500 and so on. And most importantly to be able to make call recording