use psych to study for ck and keep studying throughout your IM rotation. Step up to Medicine is a great book not only for your IM rotation but also CK. If you really study for IM during your IM rotation and have gone over everything else during psych you will be good. Get First Aid for CS. That is the only book you need. Take it at another location besides Philly (I heard that it was harder there). You don't need 2 week to study for CS. I took mine in Houston and the cases were right out of the book.
Dr Crispy, MD
PGY 2 Family Medicine