Recommendation for Z77 and 2600k memory

[FredBasset]

I'm going to order the Asus Z77 Maximus V Extreme tomorrow to go with a 2600k I have that will do 4.7Ghz. The current board I have is failing and the Extreme has some features that are useful to me.

I want to get some better memory than the 1600Mhz Corsair I have, what would people recommend?

Thanks in advance
Fred