Asterisk cluster/Joomla Interface

Asterisk Cluster with GUI Using only open source tools such as opensips or other, an asterisk distribution, need to put together the following in a linux only environment. What ever you build, it needs to be something that we can manage and grow on. Need to be able to scale from a few hundred to a few thousand simultaneous calls for a small VoIP provider service. Look at this as a one time job but, additional work would come in different forms if this is done right. NOT interested in one man shows, tired of being left hanging or having to renegotiate mid project. -Clustered Asterisk Starting with two or three clustered boxes, able to quickly/easily add boxes as needed. A registration front end such as opensips perhaps, would send users to asterisk boxes in a load balanced manner. This setup should handle redundancy and automatically fail over users for as little impact as possible for users. This could mean local servers and also additional servers at another location. -Centralized management tool Need GUI to manage everything by non technical people. For example, adding trunks, manual extensions, etc such as FreePBX would allow for example. -Joomla Interface New users would sign up on a joomla site. Using CBSubs, users would manage their own accounts and joomla would be able to update extensions/users on the asterisk side. When a user expires, so does their account (after a fair period) on asterisk unless they renew their account. Users should be able to add/remove functions, which are reflected on their monthly bill. For example, if a user doesn't need faxing, they can remove this and not be billed for it. Note that I also offer plesk hosting and it would be great to tie plesk hosting into the joomla user interface, IF possible as an optional price. -Asterisk flavors I do not want a bloated system and would like to have as many users as possible on each server and making sure that quality is consistent. The two systems that we like are Druid and Elastix. However, which ever solution we use should do the following. When users log into their joomla account, they would be able to see their dashboard or individual functions from within joomla. Joomla would call up the data from one of the pbx servers so that we do not have to run web servers on the pbx's. So in other words, if a user wants to see their voice messages, they can see them in their joomla dashboard but this would not simply be a wrapper, it would be a small php code on joomla which would pull the information from the server and display it on joomla. -Hardware The hardware to be used is as follows; Individual servers for each, mysql in a master/slave setup, the gateway and the asterisk servers. I already have a distributed joomla environment and would install one new version for this project's development. The storage is network based with small drives on each server for local OS. Shared files which do not require terribly high speed access would be over the network. You can develop this on your end, then give me what I need to replicate the task here or I can give you ssh access to one of the servers, which you can use to ssh into the rest. You must have a fixed IP of course. There are many projects out there which offer exactly what I'm looking for and the only part which is actually custom would be the joomla interfacing. I have come across many people who are building such environments so thought I would put this up for bids for someone who has good feedback. The people I asked said that putting the pieces together should not take more than a few days, tuning, a few days, the joomla interface, another few days for a total of perhaps one week's time. Of course, I wish to keep the costs reasonable and this project will more than likely lead to additional work as it comes together.