What's the best platform out there that is flexible enough to easily integrate this:

Custom Flash App

I would like customers to :

1 - Select a t-shirt from a gallery of artists.
2 - Customize it ( using a Flash tool i created )
3 - Select a T-shirt size
4 - Order it.

All this flash widget does is generate a JPG on the server. the ecommerce app should assign it to that Order/Customer, and add it to their shopping cart.

Social Features Customers should also be able to comment on the t-shirts and artist bios.

I was thinking of trying Wordpress plugins like Shopp or Getshopped or Cart66. ----- then BuddyPRess for social features. Or is Magento a better choice? thanks!