Customize nopCommerce Checkout screens

Currently we have a nopCommerce 1.6 implemented with little customization here and there. We are looking for an expert who can quickly customize checkout process to support "easy" checkout of free products (it will not require credit card info/billing address/etc). It still should follow checkout process for reporting purposes. Free product is a downloadable product so customer has to be able to download the product after "simplified" checkout is completed. Access to the test environment will be provided.