Which Z77?

Okay, so I've been helping my brother put together a gaming build, and he's able to get a 3570k for a song right now, so I'm trying to narrow down what would be the best motherboard to fit his needs and stay within the budget. I have narrowed it down to 3.

MSI Z77a-GD55

MSI Z77a-G45 Gaming

ASRock Z77 Extreme3

He's getting a R9 280x and I'm designing the build around him getting a second one for crossfire to add some longevity to the build.

He will be doing some mild overclocking with this board - Somewhere between 4.2 and 4.5ghz on AIO watercooling, so no stress on the MB

Feature-wise, they are all very close on paper. Any thoughts? 

Whats the budget for a motherboard, because as far as overclocking goes, those 3 boards are realy lack in therm´s of power delivery parts.

The budget is around $130 CAD. I know the phasing is less than stellar on all of these, but we are not trying for a large overclock by any means. I know the G45 has probably the worst phasing of all three, as I believe it only has a 6 phase VRM, but the GD55 and Extreme3 should be more than enough to support a 4.2ish ghz OC

Asrock Z77 extreme 4 maybe with 8+2 powerphase.

The extreme4 has a 8+4 power phase design. The extreme3 has a 8+3 power phase design. Plus the extreme4 is $170 CAD. Way out of budget.

The ASRock Z77 Extreme4 just dropped in price almost $50 and is now well within budget! 

grab it then ☺