I'm working on a project where I have to put online an ecommerce system which will require some good amount of custom features. I'm therefore looking for a framework which makes customization easy enough (from an experienced developer's perspective, I mean). Language shoul be PHP and time is a constraint, I don't have months to learn.

Additionally, the ecommerce will have to handle around 200.000 products from day one, which will increase over time, hence performance is also important.

So far I examined the following:

• Magento - Complicated and, as far as I could read, slow when database contains many products. It's also resource intensive, and we can't afford a dedicated VPS from the beginning.
• OpenCart - Rough at best, documentation is extremely poor. Also, it's "free" to start, but each feature is implemented via 3rd party commercial modules.
• OSCommerce - Buggy, inefficient, outdated.
• ZenCart - Derived from OSCommerce, doesn't seem much better.
• Prestashop - It looks like it has many incompatibilities. Also, most of its modules are commercial, which increases the cost.

In short, I'm still quite undecided, as none of the above seems to satisfy the requirements. I'm open to evaluate closed source frameworks too, if they are any better, but my knowledge about them is limited, therefore I'll welcome any suggestion.

Thanks for all replies.