One thing to do when first decided on just what board you will end up with is to look at the manufacturer's own specifications page. You can even go through the online user manual to see what voltage settings are standard for that board. Some will 2v to 2.2 or 2.5v even while others see 1.8v - 2v.
When not planning or in the middle of ocing memory keeping the voltage set lower will help keep temps down. As for the memory look at the voltages it requires. That's the thing there to look at.