Sip Voip widget for pre-recording calls (Proyecto En Español - Ou Tambem Portugues)

El punto de contacto para este proyecto habla español y portugues y las comunicaciones seran en español (o portugues), pero el producto final va a ser principalmente para interconectarse con la red de telefonia en usa y hasta en una segunda etapa en paises de latinoamerica, por ende el programador necesita un nivel basico de ingles tecnico y de telefonia en usa.

las especificaciones del proyecto las mantengo en ingles abajo pero cualquier pregunta o aclaracion por favor contactarme directamente.

I need an MVP right now, so I only need a simple front end since I will be the only user at first, but I need a programmer to do the back end integration.
I need a programmer to create a mechanism by which we are able to tell the backend telecom system to:
1) send a specific prerecorded voice file, and
2) send that voice file to a specific phone number, and
3) send it at a specific predetermined date and time.
I already has a semi-functional web-based front I created using forms with jotform.com. It is a simple online form which has fields to input the phone number to dial, to select the day and time to make the dronedial, and then a widget which records your voice and saves it into the cloud with each voicemail hosted at a specific url. The date that is gets entered into this form can also be synched with other web services including dropbox, google docs, google drive, etc, in addition to the standard email notification you can receive every time a form gets submitted with a recording.

Jotform is actually a good option to get started since they have a lot of integration and API options built into the platform. Or we can use even simpler tools, like google spreadsheets, or the new google calendar Labs feature which allows tu upload files (the voice file could be generated using the Voice Recorder from Windows), etc etc.
All we need is a good developer/programmer that knows how to configure to a Plivo/Twillio/Nextiva type service, in order to make the back-end work, and actually have real calls be made on the PSTN (public switched telephone network). We need a programmer that knows how to use API-based DID/SIP/VOIP platforms such as Plivo or Twilio …