Yes, you have to select the motherboard first. Motherboard vendors have lists of memory that are certified for a specific motherboard. If you buy the memory first, it may not work on the motherboard you finally settle on.
I just built two new systems, one with a gigabyte Z77X UD5H that I'm using an i7 3770 CPU and Ripsaw memory for my recording studio. I also built (just finished) another system for general use (and recording studio system backup). It is using an ASRock Z77 Professional motherboard. The ASRock has an i5 3550 CPU. Both are working well and low latency (after I uninstalled a gigabyte utility that was hogging CPU).