Bare bones paypal plugin

Hi all.

I am in desperate need of some help integrating PayPal into a WordPress theme I have developed for a client.

All I need is a simple way of adding a “Add to cart” button with drop down menus for size and colour.

I have tried pretty much every plugin out there and I can’t seem to find one that suits the clients needs (They’re not very tech savvy)

Is my best bet just to have them use PayPal’s own button generator and paste the code into a custom field to display it in the theme?

Any help would be great.

Thanks in advance