Have you already gone through the website planning
stage of your business development? If not, then you really should as it will give you a ton of information you need to develop a successful website from the building stage right through the promotion stage.
Consider how large of an ecommerce site you want to build (now and how big you want to be in the future). While there are open source ecommerce software packages available, they might be over kill for your business and a simple site with buy now buttons would be better suited.
Learn some (X)HTML and CSS. You don't have to be a pro but with this knowledge you can make an informed decision on the quality of any ecommerce packages you consider.
There's also the SEO side of things to consider. If you read through Effective SEO - The V7N Way
you will learn what a site needs to be search engine friendly. Learning this now as you build your site can save you a lot of time and expense if you choose the wrong system.
Starting an Online Business
Starting an online business can be quite daunting whether you are comfortable with computers and the internet or not. There are all kinds of ads and articles on how to start an online business for free....
As you get ready to take your brick and mortar business, home based business or turn your hobby into an online business there are a number of things to consider before getting your business online...
If you decide to still go with a hosted solution (as the 2 you mentioned above) please make sure you retain ownership of your domain name and are able to backup the whole site
. If may say you can backup the data but you also need to be able to back up stuff like the template in case of a server crash.