Customise Open Source Software

I'm using the Siberian CMS open source software, which I have installed on my own server. This is basically a code-free, module based, drag and drop environment for producing apps. See [login to view URL] I now need to customise one of the modules (mCommerce) to suit my specific needs. Siberian CMS is based on the Zend framework (PHP) and MySQL. A few of the changes I would like to introduce are: Simplified, ‘stay-on-the-page’ item ordering, where a quick add button will prompt the user to select item options (some items will have two option groups – i.e. type of meat and flavour). The cart icon would need to appear on the bottom menu bar to indicate that the cart was active. Presently the user is directed to the cart summary every time an item is ordered, and then needs to navigate back to the menu. Text input for each item ordered (for special requirements). Text input at checkout for any comments. The ability to select the collection or delivery time at checkout, based on the restaurant opening hours, with the earliest slot 60 minutes from the time that the order is being placed. A “my orders” section where a user’s previous orders are stored, possibly with the ability to repeat an order. (the test app, above, has a “my account” section – but this is only for the Newswall module, to allow users to like/comment). This, hopefully, would allow the user to login or be recognised/remembered on subsequent visits and place an order without the need to input name, address, etc. Currently orders are sent as email, which is either sent to the restaurant as SMS (via an email-to-SMS gateway) or direct to a mini-printer in the restaurant. Would it be possible to generate and send the order as SMS?