Multiple Swfs? FlashMX2004 question

I have put together an interactive flash piece where the user can colorize and create a custom shoe which they can order - There are about 30 different images the customer can choose to place onto the shoe. Is the easiest way creating 30 separate layers and hiding all but the one they choose (will this be too big of a file then?) or should I create each image for them to apply as a separate swf that will be loaded to the main swf when they choose? And how would I code it?

Now here’s something for a real PRO:
(I still need help coding this backend portion to get the order on the server) They use a MSFT Sql server & will provide a custom asp script that you would call with the data (which shoe, which size and customization) and we add it to the cart for them and the photo. PM me if you can help.

Thanks in advance!!!