Mark Charlton did a semi-lay-forward position with easily made side-brackets. He has a Fluidyne radiator with a Flex-A-Lite fan assembly mounted over the top of the radiator (to avoid attaching through the fins) with simple folded aluminum brackets. It's very effective and looks somewhat stock in appearance to the casual observer.
There's no reason you couldn't mount a Flex-a-Lite pusher fan assembly the same way, but wouldn't need the semi-lay-forward brackets.