WP Ecommerce or the like....

Ok, there are a couple questions here. One, I'm wondering how I could allow a blog user to put a donate button or similar type thing on their blog. Is there a plugin for this or would I need to while suggesting it and pointing them to signup for paypal or the like if they haven't already have them then send me the code they get for the button and offer to put it into their selected template manually, at the same time making the template they are using a copy of the one that is for general use.

Secondly I see there are buggy issues with WP E-commerce plugin, what about qukshop? If I want to be able to allow blogs to be created in order to use as shopping outlets or the like what plugin is best to go with?