Small VoIP system needed

I have a more detailed list of requirements, was just testing the waters here to see if we had many options. We are an ISP with an existing customer base and plenty of bandwidth. We're guestimating about 100 of our existing customers would sign up to a VoIP service if we offered it based on our internal surveys.

Location: US, Virginia.

We have to comply with all of the normal US requirements. We will be using a pure SIP solution, no direct connect to PSTN. We do need a user interface for the normal account management functions. We don't need much for billing other than a CSV output file with cost for each account. We will invoice from there. The user interface should be able to show a call record with free minutes remaining and costs to date.

I'm being yanked around right now by another "integrator" that promised a 10 day delivery in Feb. It's now June, and they don't even have voicemail working yet. They give me one excuse after another, but the main problem is I was stupid enough to send them final payment when they assured me that their delivery met all of my requirements. We just needed a few hours "training" to see everything in action. 3 months later, I have a system that I cannot show to customers. No voicemail, no fax, no conf calling, no integrated user interface, no international dialing, no e911, etc. Some of these things I can do myself, but would rather just bring in a competent, reliable consultant.

I'm not interested in bashing the old integrator in public right now. But fool me once, shame on you, fool me twice shame on me :>). As a lessons learned, any new integrator will have to show me working samples to prove they have the technical capability to do the work, and final payment will be made only after demonstrating they have met all requirements with their delivered project. Incremental payments terms will be negotiated in advance.

If anyone is interested, PM or email me at steve@taylorstown.net for details.