If you took a look at my pictures, you will note that for my radiator mounting, i have two fans on the outside edge of the rad pulling air through, while using the two 120mm fans inside my case to blow air through the rad.
if you want to have them blowing youd just have to flip them over so they blow the other way.
and yes you can still use your 120mm fan, youll just need to get creative with the mounting.