Yeah, I forgot to mention, you don't have to go with Thomas Mason, but really, why would you bother? If you're going to all the trouble to go to Honk Kong to get measured up for a bespoke shirt, it seems a bit silly to skimp on the fabric.
Also, I don't get all of my shirts made up, only dress shirts and business shirts and I generally stick to twills and broadcloth. Kamakura's Tokyo slim fits me just fine and I have just as many of their oxfords as I do PJ shirts. I don't really see much value in getting OCBDs or popovers made up if there's a good off-the-shelf alternative available that fits well.