Maze4 GPU vs NV-68

[Vertigo Acid]

Currently I am using an NV-68 block on my BFG 6800GT, and it's working great, however my memory is the limiting factor on the overclock, as I can only get 1050mhz stable. Core is stable to ~450mhz. What I am wondering is, if since my memory is not being aided by extra cooling (that's the same memory OC I got w/ stock air cooling), would the Maze4 do just as well for a lower cost than the NV-68? Also, if I do decided to get a Maze4, any reason not to get a low profile so I can SLI in the future? Is the performance the same?
I'm not really very fond of the weight of the block either because I LAN alot and the card seems to sag down quite a bit.

Here's my whole setup:

D4, 2x TDX, Z-chip, NV-68, Thermochill 120.3, all 1/2" ID

Thanks