Just a few thoughts from my S7 ownership a few years ago now.
I think the radiator and fan should be enough to do the job, so what else could be the issue.
Air flow out of the engine bay was always an issue on the S7, do you have some decent vents fitted I had the stainless marine vents fitted to the side of the bonnet.
Is the water pump doing its job, i had a pump which had a pressed steel impeller these can corrode and arent very efficient, a cast impeller works much better.
Is the water flow restricted, does the engine need a flush through.
Wrapping the exhaust helps if only to stop your feet melting.
As for the push pull question, I don't think it matters as long as the fan is running in its design direction. If it's running in reverse it won't be a efficient.
Jez