Hi,
I am Abhi, a Magento certified developer . We have very good experience in Magento development , customization , extension development, database migration. As per your description, you want to convert your existing open cart website into Magento. We only need PSD of pages, we don't require HTML or PHP files and also please let me know how may product and categories do you have in your current store and their product type. We already have good experience for migrating opencart websites in magento. Regards: Abhi Axovel Software Services