Asterisk Development on Existing System

We have several Linux based Asterisk servers that were developed to operate with our existing MS SQL Server Database. The web interface is programmed in ASP.NET with some of the underlying functions for Asterisk using C/C#. We have customized the Asterisk service to provide VoIP services for our residential and business customers. Our system has been developed to provide Enterprise VoIP service (hosted VoIP services for businesses). We need to enhance this system by adding a customizable IVR capability which can be used by every new hosted VoIP customer. Primarily, we need the development of a web GUI interface that will allow customers to customize the Auto Attendant/IVR script with different voice menus, DB Select/Update/Append,etc. functionality, play/record menu options, call/transfers to different extensions/phone numbers, etc while maintaining the call features available through Asterisk, like call waiting, call forward, caller ID, call transfer, etc.. In order to provide the custom IVR functionality needed, we require the development of 20 to 25 web based GUI function boxes (drag & drop), each with several different properties that will write the IVR Asterisk script and integrate it with the account profile for a particular customer. Each of these function boxes would correspond to a particular task to be performed in the IVR process like, Play Menu, Record Menu, place a call (to extension or external phone), Detect DTMF digits, etc. The script that is created would be saved, the functions would be applied to a particular DID associated with the account and the customer should be able to load the script at any time to make changes as desired. A lot of this functionality has already been done however it is in a line programming language not a web based GUI. For this project, we need the GUI interface to be developed and integrated with Asterisk to make a flexible IVR development tool. Our current developer is no longer able to continue development on this project. Again, much of the Asterisk customization development and deployment is already in place. The major development for this project lies in the development of: - the capability of writing a customizable IVR script for every new Hosted VoIP customer (containing at least the features mentioned above) using web based GUI function boxes that write an Asterisk IVR script upon integration. - minor fixes and tweaks on Asterisk as needed to accommodate all the new development and/or resolve outstanding issues. We would prefer to work with a company that has already done this type of development before and can use some their previous development expertise (and maybe even code) on this project. The bidding company also needs to display a thorough knowledge and adherence to sound development cycle principles (tech specs, thorough testing procedures, etc.) Please note that this project is for ADDING to existing development. Our current Asterisk deployment is already configured to work with our MS SQL Server DB, have redundant IP addresses (with Heartbeat) between the two servers, etc.. We only need to have the web GUI developed and integrated with Asterisk for custom IVR development. The new developer will also take over the maintenance and further development of the current Asterisk system as needed. We will provide more specifics on this if needed to finalize the estimated proposal. Please pay attention to the requirements listed and don't send us a bid for something else as this is going to be a waste of time for both our companies. We are also attaching a sample script development tool that is a copy of the popular Envox Script Editor program. Please take a look at this as we would need a very similar functioning program developed for this project the difference being that it would be web based and working with Asterisk. Thank you.