PHP Development - Coding/Adding Pages that CMS won\'t allow.

We have a website that has been up for a long time. We had a contractor helping us with the PHP part of the website. We can take care of the CMS part here. These will be random projects such as adding icons to our main page and adding new tabs to the top. (It will be better understood once you see the website) We have a ton of information that we will be adding to this website in the near future. We can input the information via CMS, but the creation of tabs and pages will be where we need help. We are looking for someone that is reliable and dependable with response time less than 24 hours if possible. Since our projects are needed at random times, we need our developer to be on-call basically indefinitely. E-mail is our preferred method, but phone method works as well if it's more complicated of a project.