Unless your going to a higher flowing water to air side mount intercooler. I doubt that any side mount is going to be a good " upgrade"
What are you talking about??
Just about any intercooler is way better then S4 stock coolers.
There is million logs out there too prove it.
Hell, i uppgraded on my old S4 from stock to RS (which are really not that good either) and it was way lower IATs etc...
On my Big ports SRMs, i have never seen temps over 55degC standig and Ideling for a 10-20 min.
When i start driving it does not take more then a short period of time and my IATs are low.