Tange makes a couple, maybe three, different headsets based on what I see being offered on eBay. I think that the Levin is their top-shelf product, though they're all probably fine. Headsets are one area where the pretensions and obsessions of bike snobs really look silly. It's a very basic piece of equipment, without much demanded of it; yes, just about all the load is side load, and they take a lot of impact load, especially the bottom bearing. But they don't make you go faster or last longer before you're exhausted, and they can hardly screw you up, unless they totally fail catastrophically, which is really rare. The best ones are the ones that keep crap out of the bearings, so you don't have to overhaul them so often.

Your stack height of the replacement headset you need should be (1) the length of the steerer tube on the fork, from top of tube to the place where the bottom race butts against on the fork crown, minus (2) the height of your head tube (the bike frame part only), from underside of top pressed race, to top of bottom pressed race, plus (3) a millimeter or less -- that's so that the lip of the locknut doesn't bottom out on the top of the steerer tube.