Hi Boris,
I am using one of the 2-pin PWM headers to power a 7.2W CCFL and it is just fine, although I think these headers were designed for use with LEDs rather than CCFLs. You won't be able to control the CCFL as the frequency on the header won't allow it. It is either 'on' or 'off' if you use it with a CCFL. If you want greater control over the output of CCFLs then I think the Multiswitch was designed for that.
The connector for these headers is available in the AC webshop:
http://shop.aquacomputer.de/product_info…roducts_id=1629