Well you should have ~56-58mm of clearance. So a cryorig c7+ https://www.thingiverse.com/thing:3154105 + a full 92mm noctua (not the slim one) + 2x 40mm fans(I got some cheap scythe ones) helps keep the system nice and cool.
Another option.could be to buy the Deepcool GABRIEL Low Profile CPU Cooler. It is stock 60mm (with it's 20mm thick fan) replace it with a nf12x15 for compatability.
I'm still not 100% on whether I'm going to use the spacers or not - but all those options are pretty interesting.
I already own 2x 40mm Noctua's and the NF12x15 so could go for either option. I particularly like the mount though as it's got cooling for my top mounted drive.
Otherwise is it a case of a stock Cryorig C7 vs the Noctua L9?