Hello,
I would like to suggest that you first think about what you need for now, and what you might need in the future.
Not all merchants are alike... a shopping cart can be a very important tool, even more so then a fancy web design. It should do more than just collect sales data.
"One size does not fit all" ---There is no "One best solution for everyone"
Some questions to consider:
1) Can the cart be updated with not just what the cart system provider wants to offer, but also if you need a special custom code designed. If so, what are the additional charges if any.
2) Support.. When you have a question of any type, design, programming your pages, etc... are you able to speak to someone and not just exchange eMails? Are they available 24/7 and after hours?
3) Will the cart system help you expand your business? In other words, how flexible is the system to be able to add additional websites to the same system... of do you have to get a new system for each site?
4) Can you host your web sites on any server, or are you restricted to hosting with the shopping cart provider?
5) If you're a Webmaster, and you'll want a partner that can solve your client's issues. Not require them to jump through hoops to get something they need done, that you yourself can not provide.
It doesn't need to be complicated... but a little pre-thought can save you hours of time and lot's of money.
We recommend
http://www.SecureCart.com
Very easy to use and if they can provide it, they never charge for special requirements.