I did it :) thank you.
It is unfortunate though that it has to go yet to another page which looks exactly the same so the options can be chosen (we want to sell 3 different sizes).
It would be great if the post (the first one) already displayed all the shopping info that you can only see by "clicking on the shortcode" ... unless I'm missing something.
It's late so I didn't really spend a lot of time with it (3:15am here in London! bed time! :) but you can see what I mean by going to the actual post (also worth noticing that the post is already 'a click away' from the photo on the homepage... so by the time the buyer gets to the cart there's been many clicks to 'unnecessary' pages I think...)
**shopping option underneath the image...
thanks again splashingpixels!