ecommerce hosting

Maybe this isn't the best place to do this but if anyone can help me I would very much appreciate it. This is a class project I am taking where I need to evaluate three high quality/low cost hosting companies that specializes in ecommerce websites.
The criteria is:
excellent support,
high quality web development tools,
good merchant associations and fees,
low monthly cost

I am sure I'm leaving out some but that is what i can remember. Please let share with me anything you might suggest or where I can get this information.

Thank you taking the time and your help.
Craig