Hi TheGeekestLink,
I think the "PHP" is quite an odd one here, as this is a mere
language (or
technology) that is used to build websites and webapps, whereas the other three are readily-built packages (some of them extensively using the PHP).
PHP only option:
Pros:
1. You can get a bespoke solution to suit all your specific needs
2. You will most probably get the unique website solution, used by your website only.
Cons:
1. Building it from scratch takes time, so the webmater will charge you more
2. There may be security issues - webmaster will be likely to work alone, so he won't have the experience of readily-built packages' developers
3. It's really hard to manage without a sound programming knowledge
Joomla / Wordpress (you may hear Drupal as well)
They are so-called Content Management Systems. This means you can edit your site easily, just like you edit your documents in Word. They are widely-used, so there are tons of tutorials, plugins and add-ons out there (especially for Wordpress).
On the other hand, they are not designed for selling/ecommerce, so you will either need a plugin to manage all the shopping bit.
Pros:
1. Easy to edit and maintain
2. Easy to set up and design (you shouldn't be charged much + many developers can do that, hence the competition drives price down)
3. SEO-friendly (Google likes Wordpress)
Cons:
1. Security faults (they are prone to online safety threats)
2. They are lacking selling features (at least their original versions)
The last one: OpenCart is a selling-oriented package. Just like these above, it's easy to manage and install, with lots of tutorials on how to use it. It is also great in terms of design and Google search.
Pros:
1. Easy and cheap to edit, maintain and install
2. SEO friendly
3. Specifically designed for selling purposes
Cons:
1. You'll need some design done
2. Initial configuration can take some time
Summary: I would consider a few points here. First of all, if you have your main webpage build (and you're happy with that), Open chart will perfectly serve as a subpage, then. Also, give you aren't going to manage a grocery store with thousands of products, you can consider a tiny system like (
http://simplecartjs.org/); it doesn't require database, management systems and all this tech stuff and will seamlessly integrate with your design.
If you want a new website built, then look into Wordpress/Joomla/Drupal. If you are happy with the management system one of these offer (in terms of user-friendly interface that you are happy to use), then go for it and install a plug-in to sort your selling.
I hope it wasn't too geeky talk, so if you have any questions, let me know!
