High Quality SIP Trunk Providers

(I recently asked a different question on the same project. I separated the questions to get keep answers on topic, and hopefully hear from some SIP providers on this topic)

We are developing a web app, and we are going to integrate a click to dial feature.

I need to figure out which SIP Trunk Provider to use.

Projected users by end of:
2013 - 150
2014 - 1650
2015 - 3650

Each user will dial the phone up to 4000 times per month, but average closer to 2500. Each call will be placed by input from a user (not an auto dialer). On average 80% - 95% of calls will last less than 2 min, and ~25% of calls will last less than 6 sec. Successful calls will last 2 - 25 min.

Any help will be greatly appreciated. If you a SIP provider that offers services that will accommodate our need please message me.

To Greater Success!!!

I would say the the best VoIP provider choice would be the one that offers direct peering with your Asterisk server. Afcoarse the call price also has to be right. But a good network connection between the Asterisk server and the VoIP provider will be cruicial in your case.