Hiya bean_2k1,

What you have there is (as Bocaj said) a mix of flash, xhtml, a database (in this case .net I would guess from the speed) and javascript for defining the functions as well as the purchase side. I don't think any of this can be gotten anywhere as a freeware version, though having said that, I think I have seen a flash image-editor fla lying around somewhere at Flashkit or Flashperfection.com

Doing something like this is quite difficult (I tried to do something in the past and failed miserably), but for the sake of resources you would be looking at tutorials covering the following:
- XML integration into flash (all the designs and products tabs of that site are populated from a database via xml into flash)
- Object manipulation via actionscript's EventListener (resize, move, rotate)
- Object manipulation via actionscript for dynamic text
- Sourcing information from flash into an eCommerce engine (or paypal integration)

Unfortunately where I am right now (train) I don't have all my bookmarks on me, though the books I would recommend you read up on would be "Learning Actionscript 3.0" (O'Reilly) and most definetly "Essential Actionscript 3.0" (O'Reilly), as these are both very good starting points as well as wonderful reference books for anything object or xml orientated in Flash.

Hope this kinda gives you a starting point into the matter, once I am home this evening I'll add a couple more links for you to have a look at.

Alex