Update OscMAX web site from 2.0 to 2.5

I need an OscMAX web site to be updated from version 2.0 to 2.5. It is a working site and I have the new site set up on a sub domain. I need my modification and modules transferred across and tested. OscMAX is a modified version of osCommerce. The modifications on the web site which need to be installed such as. Second address line Referral enhancement Send a custom email when order is placed, or a button is pressed on the record. (custom mod on my site) Neaten record (apply ‘proper case’ to customer names and addresses - to remove bad customer formatting). (custom mod on my site). Warning message when some options are chosen (plus power lenses rather than minus power lenses). (custom mod on my site). Custom shipping modules Custom payment modules. Some custom modifications need to be made to the ones on my site. I don’t currently have a splash screen and people press the payment button twice and get charged twice. Maybe the checkout button could become inactive and greyed out once it is pressed to stop this from happening. Data will need to be transferred in MySQL tables. eg customer details, product details. Cross Sell details. Some tweaking will need to be done. Eg To get the front page looking similar to the current web site. Remove the “buy now” button from featured and cross sold products. Remove the “customers also purchased” list of products which slows things down. Also in the tweaking section I will expect a few other things will need to be done and perhaps some other addons will be required which I have fogotten that I have in my live site. One tweak I need looking at is that OscMAX allows multiple price points for different products eg $35 for one, $32 if you buy 4 or more. If you order 2 of the product of one option and 2 of the product of another option the reduced price is not given. I would like the reduced price to apply even if different options are chosen. Stages of this project. I am thinking that the products would need to be transferred and mods installed and tested first, and then when OK all the customer details to be transferred across and go live. Let me know if there are any questions.