Hi Omoba!
Let me first introduce myself. I'm Web developer and I work in a team that specializes in the development of almost all types of websites. The team includes graphic and web designers, project managers, mobile developers, SEO developers and PHP developers. In a word, we have a whole logistical support to make your site with quality, optimized and visited.
Regarding your project, you described very well your requirements.
All these tasks (creating of Contestants page, Database upgrade, validation forms, random galery on Home page) I can do easy in Yii Framework. I don't know how much you are familiar with MVC frameworks at all, but they offer a great support for all stuff you need.
The second way, without using Yii, is to upgrade your code, but it's not so good option.
I hope that my proposal is understandable for you, so we can continue conversation via skype. My name on Skype is demijan126.
Cheers!