Product Attributes = different SKUs?!?!

Quick question.

I sell lingerie and offer identical products except that things come in small, medium, and large. Instead of showing the same product listing and image three times, one for each size, is there a way that I can set an attribute for one product and they choose the size as an attribute and when they hit order, the related sku would be added to cart?

Example skus

REDBRAsm
REDBRAmd
REDBRAlg

So in the products I would add the image and product image for REDBRAsm (its the most ordered) but if the user changes the attribute to Small or Large, the associated product sku would be passed to the basket INSTEAD or REDBRAsm.

Hope this makes sense about what I am asking.

I think you can achieve this with the Stock By Attributes module in the Free Add-on Section.