I would suggest my Asus Prime x470 pro unless you want to go for x570 chipset. It needs newest BIOS (v5007) to work properly but with it and 3700x works fine. I'm getting boosts up to 4,37GHz and memory works at 3600 MHz.
As far as I know, none of MBs with 400 series chipset work (yet) with 3rd gen Ryzen out of the box. Will have to ask seller about it and possibility to do it for you.