100m tower cooler? I don't think you'll find one that's sufficient.
So a tower cooler that will do the job is out of the window then?
Most people seem to be recommending them.
You need something like the Noctua C14 that is a top-down cooler, but will get good cool air from the side fan you have.
I was myself looking at the Noctua as people seem to hold them in high regard. So, what you're saying is that if I set up the fans to blow down onto the CPU then my side case fan could actually benefit CPU cooling?
I've never used a low profile heat sink before (discounting stock ones) so I'm a tad wary.