i stumbled into studio porter jensen by accident - i was looking for a cool silver ring at 'something silver' in u village and ended up a door or 2 down at porter jensen. not only do they have lovely merchandise but their customer service is excellent, as is their craftsmanship.
i bought a ring from them (i worked with elisha) and they did a perfect job resizing it. i later brought them a sapphire stone and had them set it into a gold ring for my mom for her 60th birthday. i was practically speechless when i saw the result - it looked even better than i'd imagined! and their prices are extremely reasonable, too. http://www.porterjensen.com/ is their site, and they've been around for a while.