E-Commerce integration (online checkout) for a tour reseller

My company sells guided tours primarily for Asian customers. I have a website setup showing all my guided tours at [login to view URL] This website is built from Joomla CMS, all the tour pages and search functionality is provided by a CCK module Form2Content - [login to view URL] I am looking for a way to provide online check out for all of my tours without completely restructure how it is currently setup (at least for now). Now, I have done a lot research and the closest extension that came close to my needs is Payment Form [login to view URL];view=article&id=67&Itemid=52 (if you are interested in the bid please check out why). Unfortunately Payment Form lack several important features for me to utilize, so here I am. Here is what I need in ADDITION to what payment form is offering -CHECK LINK ABOVE **Backend** -pull all the articles under designated categories and list them as a tours (inventory items) -Inventory, such as available seats per tour -seasonal/calendar pricing (variable pricing depends on the week/month/season) -build foundation for multi language support -order processing (automatic mode, call to confirm, refund, additional charge, comment on orders etc) -record statistics **Frontend -calendar showing all tour dates and it's pricing -pricing calculation breakdown -check out process (multi page, optional account registration etc) -shopping cart -simple,fluid design (style and process) -AJAX/JQuery -FAST FAST FAST here are some of my competitor's website, you need to be able to at least duplicate the functionality of the sample site below and much better [login to view URL];a=product_view&p=4788 [login to view URL] (this is in chinese, but if you scroll down and play with the form entry you will see how it works) My experience with e-commerce is limited, I want potential bidder to look at my website from all angles and provide feed back, suggestions, process improvements. I am looking for a long term partner, as this is the first step to expand my store. You must provide a showcase site for me to consider your bid.