Want new features and design to my penny auction like swoopo

Hello, I have a penny auction site similar like bidstick, swoopo and etc. Our site looks more like bidstick, but we want a new design and new features on our site that we want is: auto bidder, bidbutler, other options of payments and etc, but needs to all work withouth minor and big errors. also I already have members on our site, we would like to still have them, so we need a script looking like swoopo with all the features like swoopo and bidcactus, but with the same members. I will pay $30-$200 max thank you