All the coursework you mentioned will be important. Also try to teach yourself neuroanatomy from the appendices of an intro neuro text. (Learn the regions and subregions of the brain and their basic functions). I would argue that a class isn't necessary since it's mostly memorization.
Depending on how deep you want to delve into fancy fMRI analyses, it may be useful to take some coursework in physics, calculus, and statistics. If you want to do more basic experiments, this would be superfluous. But bear in mind that these concepts are very commonly used in your field. Familiarize yourself with statistics at the very least. PDQ Statistics is a good, short introductory book.
Learn MATLAB. This is critical for cog neuro researchers. You don't have to be a maestro by the time you enter grad school, but you should be flexible with the program. Read a beginners text like "matlab for dummies" and practice at work. Ask your PI for some datasets you can fool around with.
More important than your resume is your familiarity with your field. Coursework is important, but always leave time to read relavant papers in your field, especially from potential advisers.
Anyways, you seem to be on the right track. There's only so much you can do in a year and you seem to be a strong candidate already. Best of luck to you!