I am tasked to build a shopping cart that sells book. I would like to seek help in putting me in the right direction as to where to go from here.
As of what I see, I
You have couple of options
Both of them are built for e-commerce.
Magento is slow without any doubt, opencart is fast but not the best as Magento.
If your's application scope is limited, you can build the application in CI and i knows that it will be faster than both of these two.
But as programming perspective, its always better which is already build instead starting from scratch.
There are many things to take into consideration here.
Building a online store is no simple and small task. A small store with a flow like this add product to cart -> go to checkout -> pay using a third part payment provider
could be accomplished quite easily and fast. But here are some more considerations:
I could go on for a while and make the list more and more specified, but I don't really have the time for that :) And this was just to show you that there are a lot of factors that comes in to play when building an online store.
This is an excellent choice if you are an experience developer and familiar with the Zend framework (which it's built upon). Take a look at the features for Magento, pretty much anything is possible with Magento if you know how to customize it correctly. This is not an easy task if you're not familiar with it and the learning curve is very steep.
This is a bad choice if you're not experience or the store doesn't need all of the advanced features. It's a resource hog and if you don't know your caching you will have a bad time.
If you need to setup a online store in a hurry with a stable environment and you can settle with having the features they offer, I would say this is your best choice. Well actually I would say that at least 90% of the times, this would be the best choice.
You won't have to worry about payment implementations, backend development, support, hosting, and all the other things that comes into play.
I've only listed 2 options here, one advanced and one more simple on. I think you should really investigaste the different options. Take a look at their features, how much they cost, etc. Then you have to take that into consideration vs the time it will take for you to complete the store.
At least I hope I gave you some perspective on this, just let me know if you have any questions on what I wrote.
I recommend Zend Framework to building shopping cart site. If you want to build from existing tool use Magento. Check Front End and admin end here
You can create your custom module or download free modules and can purchase developed module from magento.