Thousand Sound also does reshells and makes a dynamic hybrid custom IEM, but they said they only provide the service in China. You may want to contact them, but I am not sure what they will say.
G-customs is sold through the Audio Hub (and possibly one other place soon). The Audio Hub website is under construction, but they have a contact page with all the contact info. Louis did say he is only interested in selling to his local area for customer service reasons, more than likely due to shipping and customs.
I would guess the LS5X will turn out like the Merlin, but more than likely with the LS8 sound signature, but we shall see. The LS8 designer did leave Rooth and started G-customs.
There is one NT6 review that I know of here and here. As far as pricing, the first link shows the price as 979,000 as of May 2011 which is about $900. Hidition did say the price is not yet set so I am not sure where it will end up.