Best 120mm CPU Cooler For X51 - examples

Decided im going to mod my case to get those CPU temps down. I've seen a bunch of folks go for the 90-92mm Noctua solutions, though does this really give enough of an improvement over the 80mm OEM? doesnt seem worth while?........thoughts?

But I also seen this german guy went for a 120mm Xigmatek and surprisingly it fit too, unfortunately the Xigmatek Junas which he used, is no longer available. https://www.youtube.com/watch?v=0rflB5Z7S_M&t=169s


I also seen this thread where the guy used a 120mmm Thermalright 100 Muscle to great effect, but required a custom shroud (which I guess we wouldnt need with the case mod..) - https://linustechtips.com/main/topic/450273-x51-cpu-cooler-solution-and-gtx-970/


Have any of you upgraded the CPU cooler to a 120mm and can you advise on any alternatives to the above examples? 

thanks for your help.