I would also say MX Brown in your case. Here's a few things to consider:
As for the noise, it is dependent on how loud your office is. There are people using MX Blue at my work but the fan noise from the vent is loud enough to cover most of the background noise. So in contrast the MX Blue isn't too noticeable.
I don't usually suggest o-ring because I find it kills the feel of the switch. And the whole point of buying mechanical keyboards is that it feels good.
As for double tap, I'd say MX Brown is noticeably easier to do quick taps. Yes people will argue that you can still double tap with MX Blue. But it's like saying you can still run with sandals, however if you have a choice you'd run with running shoes.
Personally I like Brown over blue because Brown feels more responsive and react faster to quick taps. Blue's reset point is about 75% fully lifted up, while Brown is about 50% fully lifted up.
That being said, it's still entirely up to you but chances are you won't end up with just one keyboard so don't worry too much about it.
