hmm...
with absolute zero airflow the enzotech will beat it due to superior design. with regular(crappy) case flow id say the nexus due to what ze reviewer found(higher) out...with the same airflow going tru them..hmm...id say the enzotech again(thing is wich way?)..if i were to get it(ill explain a bit later :D) id pop a fan o nthere and have it suck air away from the sink..this warm air would go into the normal case stream flow and out the back or upwards towards psu fan/top case fan.
was looking at the thermalright and it looks liek the hr05 sli would work best in me case. ill explain why. i have an ecs 650i sli and if u look at the palcement ofthe 650i chipset u will notice tehres quite some space there.
also im using a silent whisper heat sink, and by mistake i mounted it to blow air towards the bottom psu fan..looking at it it gave me the idea to mount the hr05 sli in there so teh cpu fan does 2 jobs : 1-sucks air from the thermalright, 2-blows it tru teh heat sink. now, i liek the sink itself for what its worth but a lot of the air never makes it towards the end of the fins, it rather splashes left and right but thats another mod :D
if me darn host is up ill post some pics...:)

and for the southbridge cooling i was thinking of this :
