For Paypal - Powerstore requires Paypal Website Payments Pro - This is not the standard free Paypal account. a PP Pro account is $30 per month.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.