What is the best IDE for development with CI

As @mwhitney I highly recommend setting up a local development server to preview you sites/builds.

I use Sublime Text 3 and recommend it. It is simple and fast at its core and as mentioned, it as tons of plugins that you can add to get the functionality you need.

Plugins that I use

• Package manager (install first, later used to browse and install all other plugins)
  
• DocBlockr
  
• Alignment
  
• GitGutter
  
• SublimeCodeIntel
  
• Autoprefix (CSS3: webkit-, moz- and so on)
  
• SideBarEnhancements - Add a lot more functionally to the right click menu for the sidebar
  
• SublimeLinter - Linter that have multiple add-ons for scss, php, phpmd, phpcs, json, coffee, annotations and more
  

And on top of that you have skins and color themes to get the design you want when coding.