Simple online shopping cart solution?
 

I am looking for a simple shopping cart that require a lot of customization and just works. I will only have 1 category, different sizes, so it should be something pretty simple to put together. My merchant account is through payment alliance international, they said they can work with just about any established cart out there. I can't use a pay pal check out or I could have a cart up in a few minutes....

I have hosting already through Surpass hosting, so I just need the cart, not a hosting package.

Thanks for the suggestions