another shopping cart

I need a SIMPLE wordpress shopping cart installed and set up with 6 catagories. Must have stock control and set up for selling digital downloads as well as regular products. Should have a drop down for 6 variations that can be used with the product description. This must be a very SIMPLE to use cart that does not mess up my template. I tried installing a wp-ecommerce cart, had it in and working great in less than 10 minutes but it messed up my template. The cart will only need paypal as a payment method and us postage as a shipping method. Please list name of plugin you would use with the bid amount so that I can check the shopping cart out before you install it If it has a demo, that would be a plus. I had someone install a shopping cart and they installed a jigoshop. The add product and variations part works some of the time but not other times. I must have something that 1)works all the time, 2) must be very simple to use, 3) meets the requirements I have stated, 4) is search engine friendly, 5) does not screw up my template. Please make sure you understand what I want before you bid.