I'm hoping someone can help me I am trying to achieve a layout similare to the copy blogger blog. (can't add links yet)

So two of the posts are full width and the rest are in a grid format.

I've managed to create a grid layout (by reducing the width of the content box and floating left) but not sure how to add the two full width posts at the top. I've tried adding a query box but that adds it to every page not just the homepage. Also I have tried conditional tags to show the query box only on the homepage but cannot get it to work.

Is there a better way then using a query box? Since I have to tag the two posts I want full with as featured.

Thanks for any help