Zen Cart, is a awesome little app. It does everything you'd want from an online system. Customising the store/ the admin itself may seem daunting, but don't let that distract you.
I find it easy enough to markup client side first, and then go a head and add the bits of server side code for each page (respectivly).
It really is that simple, Depending on how comfortable you are with html,css,js,php of course.
You will find parts of Zen that you just can't f with, and you will find includes that refer to files like fcked_editor and theres no doubt you'll find inconsistencies with the code...but hey..it's a free product..and it's a very good one at that
"if you want to be the best, you have to live breathe this industry
Steven Carlisle 2006"