Paypal only shopping cart script

I have a good domain, several suppliers for my product who will ship straight to my customer. Now all I need is a good shopping cart or web store script that only uses paypal. I need to find one that isn't easy to hack or doesn't have hacks already installed by the creator of the script. Any reputable scripts out there? Any put out by paypal?

I dont want it loaded with image matrix's and other difficult to edit crap. Something very customizeable so I can make it look unique.