Please someone correct me if I'm wring on this one, as I am not 100% sure, but I'm pretty sure that a hidden semi-integrated style headset requires a special head tube. For it to be hidden, the bearings actually need to fit into the entire headtube, which on a classic 1" headtube steel frame simply cannot work. If you just place the steerer into the headtube, and look at the clearance around the sides, theres no way you can fit bearings and a bearing cup in between there.
Out of all my bikes, only one has a hidden headset, but the headtube is flared out on the top and bottom, actually making it impossible to install a traditional headset.
The type of headset that will fit is determined by the frame when they build it. So no, you can't convert from a conventional 1" to hiddenset.
Much as you can't convert from a conventional 1 1/8th to hiddenset either.
(there are a couple of places that make convertors, but these are usually to make a headset smaller, i.e. lefty/headshock to 1 1/8th convertors and the like)