Build an Online Store

Some background: we supply a subscription software package and given the industry have typically quoted rather than allowing end users to purchase online. The package is cloud based and we're looking to address this by offering several variations on the software product subscription. Essentials, Professional and Enterprise. We require a secure online purchase option (cart) to be added to our website for customers to be able to buy our software products with minimal intervention from us. Specifically we need : 1/ A new feature matrix HTML page comparing software versions with Buy now links for Essentials and Enterprise and a Quote me option for Enterprise. 2/ Support for PayPal as a catch all payment option 3/ The ability to handle customers from different countries and the use of different payment gateways (we have a merchant account in the US and one in Australia). Will listen to your advice on this matter. 4/ Importantly, as part of the checkout process we need a checkout that will allow us to easily up-sell additional modules, services or if they are purchasing the Essentials version encourage them to buy the Professional. I'm not sure if you've ever experienced a GoDaddy checkout process but something 'like' this although not so in your face would be good. 5/ The checkout process needs to display and seek agreement to licence terms and conditions and our privacy policy. I'm happy if this is a check box next to a link that they "Agree" to the terms. May have different terms depending on their country but again I'll listen to your advice on how we can implement that. 6/ Have their basic contact info create an entry in our CRM (SugarCRM) upon collection and if possible into Zendesk via the Zendesk API. 7/ The checkout process should send a notification to us internally of the new sale so we can provision their database 8/ The checkout process should send a notification to the customer, nicely formatted using a HTML template or similar, that welcomes them and provides links to getting started etc. Please feel free to contact me for more information or a link to our existing site. It's hosted using SimpleCMS currently.