Hi, pretty much same problem.
Successfully installed El Capitan with integrated graphics. Now I'm trying to install Nvidia web-driver for my Video card; So, I need to install AGDPfix 2, which requires to disable SIP option. That's why I'm trying to get to recovery mode terminal. I already tried all buttons and combinations(command + R, Alt, Alt + R, Alt + command + R). I have usb keyboard(idk, maybe thats the reason) Leopold fc660m.
P.S. Really new in all of this.
Thx for any advice!