The new Ricoh GR IIIx camera should start shipping this week in the US (on October 15th) according to the product listing at Adorama:
Ricoh GR IIIx camera pre-order options: Adorama | B&H Photo | Park Cameras | WEX Photo.
Ricoh GR IIIx accessories (US): GT-2 | GA-2 | GV-3 | GN-2 | GC-11