Buy templates with full source code, including all PSD files. Payment is securely done via Paypal. You do not have to create a Paypal account to pay, it can be done with Visa, American Express, Mastercard and other services.
No registration is required for buying the templates, but you’ll have to register if you want to download the free css templates.

If you decide to download the free css templates, you will have limited editing options. You can not remove the backlink or copyright in the footer of the template. You will not be able to edit text such as logos, because these are made in PSD format, and you need the PSD file to edit.