Customize editor toolbar with different options for different elements

I've successfully customized the CKEditor toolbar for the main body text field, however I want to allow a different set of editing options for the headline field. I only want the editor to have control over things that don't break the css styling. For example, in the headline field I only want an option to adjust font-size. In the body text field, I DO NOT want an option to adjust font-size but I do want a few basic styling options that I DO NOT want in the headline field.

How is this achieved?

ALSO: I included font-size in the CKEditor config.js but it doesn't appear in Perch? Is this because the font-size is hard-coded in the CSS, or...