This is clearly a question about looks(which is subjective) and not towards actual cooling; one of the most expensive 240mm Vs one of the most expensive 360mm, on a cpu that does at worst, ~140w...
Could throw a Liquid Freezer II 240 or 360 A/RGB at it for far less.
Pick the LCD you like the look of more, though:
-the Z73 will only fit in the front. Using the fans as pull would be more effective, but then you can't clearly see the LEDs from the front. Too bad that glass panel is there; it would've mattered less.
-the H100i can fit both front and top.
If you have other Corsair/NZXT gear, then match 'em up, don't mix; having to run both iCUE and CAM on the same PC doesn't sound like a good idea.