Thoughts on Shopp or PrestaShop?

I recently switched my WP blog to the Atahualpa them and am so happy with it. This theme is so easy to set up compared to the one I was using. Now I want to deal with my online store. I currently use zen cart, and am looking into something different because zen cart is so hard (for me anyway) to upgrade. I want something easier, but still looks professional. I've done a lot of searching on the web, and am considering either the Shopp plugin, or Prestashop.

With Shopp, I've read negative comments, but their live demo looks so great. I think because the way I have my blog set up, if I use a wordpress plugin for eCommerce, it might be better to set up a separate blog for it, that looks like it--mainly because I already have content in my right & left sidebar, so adding shop widgets would be too much. BUT, if I do that, I want to use something that will allow me to have a widget on my actual blog that shows new products, or featured products.

Or, is there a way that I could specify on eCommerce pages, only certain sidebar widgets show, and vice versa (on my blog posts, only certain widgets show)--without having to specify each page in the css inserts?

I'd be interested in what people have to say about Shopp & Prestashop. I currently have about 300 products, some with variations. I tried out Cart66, but it didn't seem like a good fit for me due to the lack of sidebar widgets.

You can check out my blog at http://www.TraciBunkers.com/blog