Hope this is the correct forum for this type of question?

I have a straightforward product line database with around 20 items.
I've looked at Mal's and Paypal carts, but don't like the extra layer they add to the payment gateway (which will be Paypal).

I need to incorporate a cart into a site that currently exists. I've seen templates for Zen, but wanted to double check it could be integrated without these. I've got some conflicting feedback from comparison sites/discussion forums.

What's it like to use for basic stuff like add to cart/view cart, display item count etc.? (Assuming a basic understanding of php/mySQL.)

I'm happy to put some more effort into looking further at Zen Cart, but wanted to check the basics first before I started installing it.

TIA,

Debbie