If sound reduction is a biggie for you, I'd say Cherry browns might be the answer. My MX-8100 is pretty quiet (about the same or quieter tan most dome boards I've used), and most of the noise is because I tend to bottom out the keys when I type "fast" (for me). If I'm going a little slower and paying more attention to the tactile feedback, it's very quiet (not quiet silent, especially the spacebar- it has a "springy" noise on release). It's also a nice, really solid board. Kind of big, though and the keys are laid out a little oddly. Plus, of course, the touchpad takes up space. I've gotten used to using it instead of a mouse, though, so if you use it, it ends up saving desk space and motion- it's closer than a mouse would be on even a tenkeyless board. Also, the double-shot keys have a deeper click than the flimsy keys on most boards.
Of course, there are also other Cherry boards with browns and double-shot keys- but I don't have any, so I can only discuss mine...