Upload & Sell: On
...I would like to do maybe a 4 to 1 by knocking down the popups intensity thru the camera, is that usually possible? or do I have to physically diffuse it down 2 stops somehow.
"Usually" it's possible and simple: you set the pop-up as Master, and the remote as Slave on Channel B. You then set the A:B ratio to whatever you like, and the camera -- if in ETTL mode -- will send out metering pre-flashes, set each flash to the correct exposure, and trigger them in sync. You can also set the flashes to Manual mode, and set the power output of each seperately.
That's the usual way; with both a pop-up and a hot-shoe flash at the same time (which I didn't think was possible) I don't know how you'd do it. The camera has to know which flash is which.