WAT DO U MEAN BY CHANNELS?? I PLAN TO FILL THE 4 SLOTS WITH 8 GB SO THAT I HAVE 32 GB ONE DAY.
If you have a large need for RAM, only purchase 2x8GB sticks for now so they can run in Dual Channel mode. You will have more memory bandwidth this way, and you don't need 32GB of RAM unless you're doing heavy workstation rendering.
**Also, purchase a graphics card with a custom cooler attached to it, preferably one with two larger fans. Larger fans need to spin slower to create the same airflow as small fans, so you get less noise.