Lottery website - design and coding required

My name's Ray - I will be working with my son Tom on this. We need someoone who can offer a design as well as a coding facility. Here is an overview Overview: On the home page visitors will see a random selection of prizes we have on our database. They can select one of these prizes or click on a category button eg: fashion, to select a prize in that category. We may need subcategories as well eg: shoes – so we need a flexibility to create categories and sub categories as we need them. Each product will be assigned to a category/sub-category. (see later). To win a prize a visitor needs to become a member ie: register on the site leaving personal details and their credit or debit card information. This will enable them to buy a ticket or ticket to win that prize. If we decide 500 tickets need to be sold to cover the cost of that prize, the site will generate ticket numbers 1-500. Because of UK gambling laws these “tickets” cannot be directly entered into a draw. The member must also answer a simple multi-choice question. Only if they answer that question correctly will the “tickets” they bought be entered in that draw. Because we have their payment method on file – any future purchase of tickets can be made without them having to re-input these payment details. We will then manually choose a winning ticket using a random number generator and notify the winner. The site needs to work seamlessly as a website and Mobile app. (We notice that sites like Wix allow you to build a website and then alter the layout to suit a mobile configuration. Having said that we don’t mind what platform you use.