Build an interactive website

I am an entrepreneur looking to begin another website. Currently working in a partnership and seeking a website developer (no design/styling required) to create a fully user friendly interactive website hosted on a VPS. I am looking for somebody who can stick around for a while and continually add and develop this website as required. I currently have a stylist so subtract that from the big picture. Onto the website itself. What am I looking for? I will be desiring two major interactive components on this website. Firstly, I will need a marketplace. Users need to be able to upload their own items (with pictures) a little like the way GumtreeAU works. Sellers can add an asking price to their item, and buyers can make offers with the online currency. This aspect of the website is relatively similar to that of any clothing store layout, however with users uploading their own items for sale. Secondly, there will be a jackpot feature on the website. A random pool of items (supplied by the website owners) will be available for grabs. It works like a lottery. x amount of people buy x amount of tickets at a set price (from the online currency) within the lottery. In turn, based on however many tickets they purchased and however many individuals there are within the lottery, they are given a predicted percent chance at winning. After a time limit expires, a random ticket is selected from the purchased tickets and the winning person is awarded the items in the lottery. They will then be asked to fill out a shipping form so that items can be posted. The main idea is that a customer is able to buy x amount of tickets and win a lottery of items. Users will have their own personal account with a payment method linked, as well as their DOB and other personal information. This account will be used on all aspects of the site including chatrooms, marketplace use etc. Each account will need show how much of the currency they have bought from 'us'. This currency is then used throughout the site. To put it simply, I will need a database to support; - Personal accounts and information - Development of a 'currency' in return for payments of real $ value (e.g. people buy 100 coins which they are then able to use to purchase other items. - Credit card payments/paypal/bitcoin etc. As of now, these are my two priorities as I would like to begin development as soon as possible. Once on board I would share private and more detailed information in regards to the functionality of the website and what is precisely required. I am from Australia and would like to be able to communicate at least once a week on a weeknight/evening. Also, expectations regarding the standard of working are exceedingly high and I don't want any dodgy back end development, clean simple and easy to add to/remove. If there are any questions or concerns feel free to ask! Thanks heaps, Stefan