HSD makes high-quality spindles in Italy; they would be the best in terms of accuracy and lifespan. Even the Chinese use them on their higher-end machines. But I'm not sure any of these spindles are really suitable to use in an office, if you want to get anything else done while they're cutting. It's not really the spindles themselves or their cooling systems that make most of the noise, but the action of the tool on the material. Then you'll probably want to run a dust collector as well, which is also noisy. Can't you rent a nearby shed, garage, basement or something to put this in?
Andrew Werby
301 Moved Permanently