Laura -
I know it's tough - me and my sister used to fight all the time. But it's actually something kids need to learn how to work through on their own. If parents always intervene, then they don't learn the skills themselves.
I would start thinking of this as "independence training" for you
Find something to do outside for ten minutes. Take your camera out to take pictures of something from lots of angles. If the house catches on fire, I'm sure you'll know
Get yourself used to letting the kids learn those coping skills!
On the noise side, one solution is to spend time outside if they're inside and visa versa. Another solution is to get yourself some noise-canceling headphones (which I *highly* recommend) and play some relaxing music while you work or read. A third solution is to teach the boys that a certain period of time is "quiet time" where they can do something quietly - read, watch TV, play video games - but that the noise levels need to be low for that time. You can start with 1/2 hr and move up from there
Rotate between all of them!