Customizing ZenCart

Need some customizations to the most current version of ZenCart. Would like the ability to upload html templates and have the option to preview and choose one on the store admin area. Would also like the ability to upload buttons/images for category and page navigation and also an image gallery.. so that images/photos can be uploaded in the admin and displayed on the website for visitors.. maybe have the images categorized also.? There may be some other odds and ends needed along the way too and this could be an on going project for someone as I will have frequent requests for more features.