[cflsystems]

If it's just one product you can always use an if statement to not show sidebar and topbar. You have to know the productid and surround the header and sidebar of your site with this

{if $product.productid eq "1234"}
show new logo
{else}
old logo
{/if}

{if $product.productid ne "1234"}
show sidebar
{/if}

but like JWait said after clicking on add to cart or any other existing site links it will use the default cart