Add of SMS capability to IEM (Interspire Emailmarketer)

Hello, I need to add SMS sending capability to Interspire Emailmarketer. I have already chosen an sms gateway, api-documentation is attached I want to use the same User Interface of IEM to add SMS capabilities to it. Features that im looking for are the ability to: 1) People can text a keyword to a number to automatically subscribe/unsibscribe to a list and at the same time receive an autoreply "thank you for suscribing" (same thing when they unsubscribe). Also be able to import cellphones via csv, manually and via webform. 2) Broadcast. Send 1 SMS to all the list. or send 1 SMS to 1 contact or segment on the list. Already done in IEM just need to SMS capability. 3) Schedule sendings. Already done in IEM just need to SMS capability. 4) Autoresponders/drip SMS, exactly the "autoresponders" feature on IEM: the ability to setup a series of SMS to be sent at certain days. Clear example: Bob subscribes to a list and then starts to receive a given set of SMS, the first SMS on day 1, the second sms on day 3, the third SMS on day 6, etc exactly as the autoresponder/followup functionality of an email marketing service like mailchimp, aweber, etc. Already done in IEM just need to SMS capability. 5) Create user accounts on the system for my clients to let them manage their own SMS (so it would be a normal account, not an admin accountand they only can see their own list and not the rest.). Already done in IEM just need to SMS capability. 6) Reports for SMS (delivered, failed, opens i think its impossible for SMS), and amount of SMS sent/credits use. IEM allows you to limit the email credits per user, i want the same but also for SMS, so you can cap a users email AND sms credit. Please understand that the idea is NOT to build a second application inside IEM. What i want to do is use the same way the contacts are stored in the database but enhancing the functionality to add the SMS features listed above. What this means is that i should be able to access a contact's data from IEM like the script works with the only difference that im gonna be able to see the cellphone and sms activity also. Regarding the UI i want the make little tweaks to the current IEM UI just to be able to add SMS, without much changes, perhaps only some buttons and a top menu section. I'm also open for better ideas to integrate SMS features into IEM than what I have described so far. I am sure that this kind of extra functionality to Interspire Emailmarketer has been created many times before. Please only bid if you have experience with integrating sms with Interspire Emailmarketer from before. Please also mention in your bid if you already have a system ready that you can setup a demo on.