Build an Open Source SMS Gateway without a SIM for Irish Cell Networks

Hi, I need to reduce company overheads by eliminating our reliance on Clickatell and other subscription services for bulk-sending SMS. For this reason we are hoping to build our own SMS Gateway where we can bulk-send SMS Text Messages for some services we are running across Ireland. We are looking for providers to offer proposals on the best solution that would suit our needs based on a number of criteria. We are open to all suggestions and we will select the best proposal to help us integrate the new system into our architecture. We are happy to consider pre-existing technologies or a new service, if you like. There are some open source technologies such as Kannel ([login to view URL]) but they need to meet the criteria below. However, if there is a hosted option that is dramatically than Clickatell/Twilio then we will happily pay for it. We just cannot find it! The main features we require are as follows: 1. Strong preference for the application to work on a Windows 2008 Server Environment. 2. We host our servers on Amazon EC2 and want the application to run within this environment 3. We do NOT want a solution where a SIM card of mobile phone is required to interact with the service. 4. We need Sender IDs integrated into the service. These can be numeric and alphanumeric. 5. There should be an API so we can bulk send SMS with a single request. There is a preference for a single HTTP request here, with up to 5000 recipients in a given delivery schedule. 6. There are 5 mobile networks in Ireland - the application needs to work with all of these. 7. Message Delivery logs must be automatically stored in a MySQL database 8. If a message cannot be delivered at the first attempt, then it should be re-queued and attempted X number of times until it is delivered. 9. No fancy front end or administration area is required, we are happy to change parameters in the code if required. It is a private in-house service so it will need good documentation Some basic points for your proposal: 1. We will most likely award this project to a contractor who has direct experience in building an SMS Gateway 2. Fluent English providers will be at an advantage 3. Do not send a generic response - that's an automated rejection 4. We are leaving the budget open ended, as we are unsure about what is required. Once your proposal is documented we can discuss a budget.