In my opinion use CI to do this will be very hard and difficult.
Let's the points...
- You'll need to create manually everything, stuffs like models, controllers, views, validations etc....
- (in my particular case / company) we have problems with PHP 7 (here we didn't spend much time to discover and solve it)
- Unfortunately CI does not follow the basic of PHP Standards (PRS') - to me it's a problem.
- They have a difficult and mess legacy code from EllisLab
If you want to create e-commerce by scratch, there are other frameworks will help you do it faster and better. I can list Yii Framework 2 and Laravel as you said.
But if you have domain with CI and don't mind about the points related use CI.
