Trying to change the featured product block on homepage

Hi all, here is my first ZenCart site.
http://artificial-flowers-store.co.uk/

However I wish to change the featured products row at the top so that it still shows 4 images, but does it in 2 rows or 2 instead of a line of 4 (as you can see it is quite squashed)

In firebug i already simulated what i need to do... (simply changing the div width containing each image to 50% instead of 25%) but i cannot find a way to do this - its not in the CSS, or in any of the templates, and i cant see it in the back end of zencart either!!!

I looked at the template and it seems to be determining it through $col-width attribute - but this is ot something i have been able to change anywhere.

any help is much appreciated!

Thank you

Matt,
You images are too large, crop them to a smaller size..

That's the size the client wants the images :S, all i want to do is flow that top row of 4 images into 2 rows of 2 images.

Matt,
Have you tried this:

admin panel/ configuration/ maximum values/ new products module

1. set to 2