Magento Community Edition ?

Hi

We need to build a E commerce store within a normal layout structure, i.e. pages should be pages it also has a fairly extensive store 'ASWELL'. Hope that makes sense, basically a 3 column type layout is not an option, we require a left hand sidebar, central content and horizontal 'page' menu.

I have been looking at Joomla and Drupal in particular but they both seem flawed, and full of bugs. Magento Community Edition seems to be recommended often but with the warning that you need php knowledge to run it.

I am able to set up most any website, but the key to this project is that its for a charity and they need to be able to add products, changes pricing etc, plus add new pages, etc within the structure that is created.

How difficult is Magento to setup, and more importantly will a virtual non techy (she updates a Wordpress CMS website with basic HTML at the moment), be able to control this shop once its up and running?

The store will have around 300 products many in different colours within say 12 categories, plus around 50 other normal content page. They have a Streamline merchant account which I believe fit perfectly with RBS WorldPay, would you recommend this payment type, as they would rather not take the Paypal route?

Thanks so much in advance for any help.

Regards

Ashley