Custom Prod. Page, Charge CC, DB. Import?

I have a few questions, i am new to product cart, the company i work for has had an older version of product which i believe will ask them to upgrade soon.

I have been given a job to create an online way to charge credit cards and to also make a page where the customer will type in  a personal customer number and the date they joined our company, when those 2 fields are entered the page is suppose to do a "check" in our system to make sure that they are the real customer, if they are the customer then i want them to be able to order what they want, and use my credit card program so we can charge their card and ship out their order.

Also i have to make a page, once the users type in their customer id and their date,  i want to create a customer order page for a specific product we sell. The product page i create will have many checks that need to be put in place depending on the customers information in our system, somehow i have to make the website have these custom fields and depending on what the customer checks off on the site it should compare to our system data, if the checks go thru, then all the data the customer filled out should then somehow be saved to a database or a txt file so i can import the data to our database.. This was difficult for me to explain but i hope i explained what i need done.

Can these things be done by Product Cart? Or am i better off writing my own program(s) ? 

Hi,

It sounds like you need a lot of custom work doing potentially, however, I would DEFINITELY avoid writing a complete system from scratch - There's a huge amount of functionality you would have to reproduce. You would also have to be exceedingly careful to avoid security holes if you write a custom system.
I suspect this level of integration will be complex if you want "real time" (or close to) links between the two systems (although see the XML bit later).

It sounds like you need the products to be very configurable, so the BTO version is probably the best route for that. Can you expand on why they are dependent on the customer info?

You can set up product cart as "wholesale only" which means that customers must both be registered and approved for access before they can purchase and potentially even see the products.  Am I reading this correctly in that you have created your OWN credit card program? PC supports a lot of credit card  payment gateways & would I recommend using that route  in preference. Equally you can  create custom payment methods if you so wish - Or you could manage the payment when it arrives in your back-end system.

PC now has XML facilities for order details etc which almost certainly the best  method of  passing the data to your database.