Spire technology in UK has 49 x370s in stock, B350 arriving today.
https://www.spire.co.uk/product_details.php?spire_code=AUMBX370IGAMING-STRIX&description=Asus_ROG_STRIX_X370-I_GAMING,_AMD_X370,_AM4,_Mini_ITX,_2_DDR4,_Wi-Fi,_RGB_Lighting&top=Components&cat_desc=1&cat_id=121&show_menu=Motherboards