Convert Asp.net/mssql to Php/MySql

Our website ([login to view URL]) is a Local Restaurant Portal. It is currently built in Asp.net 2.0 using MsSql. We have been having a lot of problems with it (Server Crashing, Poor Load times and very bad SEO). We would like to see if it is possible to convert everything to PHP and Save all the Data. To see the Site, visit [login to view URL] and Select the City Staten Island. The flow of the site is Page 1: Select a City Page 2: City Page (With Search Features, Navigation Map) Page 3: Results Page after they conducted a search on the City Page Page 4: Is the Restaurant Page. Must be a Clean, Fast loading Code, Very search engine Optimized and Design improvements over the current site. Adding (Like/Dislike, Neater Review System and Photo upload for users) on the Restaurant Page. (We have PPT mock-ups design changes for the Restaurant Page. The Rest of the site can flow the same.