If you already annotated FA, maybe 4 weeks of very intensive study could work.
But if you say there are many things you don't understand in FA&/or it's not annotated, you could benefit from a more extensive prep-> after you annotated FA and understand everything-> take those 4 weeks off and have a intensive study period.
If you want to apply for residency next year, your job and Steps prep are not really compatible.
If you want to postpone your residency application till 2014, then you could do them both.
It's up to you to decide, no one can/should tell you 'do this or that'. Stay true to your learning style and what worked for you in the past.
Also read the post with other people's Step 1 experiences for alternatives in your prep.
What else did your advisor say?