I have a similar setup with my Ultra-120/HR-05, 80mm fires through the HR-05, then the 120mm fires through the Ultra-120. Tried it the other way around, but the NB didnt like the hot air comming from the CPU HSF much, dropped my temps a bit doing it this way around.
Deed to get some pics up, i reversed the back and top fans on my PC-A10, so the back fan fires cool air into the Ultra-120, the fan on the lutra-120 fires the air up to the exhust fan, which pushes it out of the case.
All are Sharkoon 2000's, 80mm and 120mm, noisy on stock volts, but with my Zalman fan controler they are dead quiet when undervolted. Got my extra bay mounted 120mm and the rear blower attatched to the 12V/5V/OFF switches, though i cant actualy hear any diff with my rig between 5V and off.