Why not try Magento Ecommerce out the easy way??
We've been spending an increasing amount of time setting up magento users worldwide. As it's such a major change from the previous generation of e-Commerce offerings out there, it really requires a specialised setup to get it all rolling. Having been extremely disappointed by some of the offerings from 'Magento Specialists' out there, we've rolled our own setup, building it into an Amazon AMI that you're free to try. We've set it up such that it will work 'out of the box', as it sets itself up for you as it boots up. All you need to do is to open the necessary firewall ports to talk to it.
I've documented the journey at //www.greengecko.co.nz/magento_on_amazon_ec2. It's still a bit rough and ready, so I'd appreciate any comments on improvements both to the web page and to any Magento Extensions that you recommend be pre-installed ( I don't think you'll need any performance ones, as I've addressed them at a lower level - and a few have trashed sites on me in the past ).
Give it a whirl, and let me know what you think.