I responded to a thread earlier in another sub forum (I think the ww one).
I'm in a similar phase as yourself, design. One of the things I have noticed, is that it is not worth it to buy anything from China at the moment. The shipping costs are insane, almost 50% of the cost of the retail price of some items. For that cost, you can purchase slightly more expensive but readily available stuff in the US (regardless of who manufactured it, I have been looking at clearpath by Technik, I have no affiliation with them). As far as head stock, the only company I have found that has something reasonably priced, is glockcnc, but their BT30 and iso-20 headstocks are pre order..who knows when they will have them no matter what they say. I hate pre ordering things and paying up front.

I'm going with the epoxy granite route, similar to the video posted above, although I am surprised I never came across it already. I have been follwing this guy.