Its be useful to know your maximum dimensions and the processor you are trying to cool (i assume you arent overclocking etc). Is anything possible whereby the heatsink could be seperated from the cpu itself using heatpipes like the silverstone NT-01 (not compatible with AM2, just for clarification). What case or enclosure has this got to fit into?
Just had a quick look, the Cooler Master Susurro is 41mm high and the NORTHQ 3392 only 27mm. These will both be pretty poor performers though compared to modern tower heatsinks and with the NORTHQ its hard to tell how noisy it will be though with the CM you can always change the fan.