It was possible to elaborate this list (considering only npcs merchants that accept gold and that are permanent):
Thais: Npc Gamon
Piece of Royal Satin
Yalahar: Npc Dorbin
Silky Tapestry
Crystal Table
Svargrond: Npc Janz
Small Ice Statue (Fish)
Small Ice Statue (Bird)
Port Hope: Npc Zaidal
Tusk Table
Tusk Chair
Thick Trunk
Small Trunk
Stone Table (Carved)
Ivory Chair
Bamboo Table
Bamboo Drawer
Banuta: Npc Hairycles
Monkey Statue (No Hearing)
Monkey Statue (No Seeing)
Monkey Statue (No Speaking)
BONUS:
These aren't really furniture merchants, but they sell special and exclusive items.
Farmine: Npc Cael
Didgeridoo
War Drum
Dragon Statue
Dragon Throne
Meriana: Npc Dunkan
Pirate Tapestry
Farmine: Npc Pompan
Dragon Tapestry
Dragon backpack
Minotaur Backpack
Bounac: NPC John The Carpenter, Folded Artefacts Carpets:
Folded Artefact Carpet I (Sapling) >
Folded Artefact Carpet II (Almanac) >
Folded Artefact Carpet III (Book) >
Folded Artefact Carpet IV (Cube) >
Folded Artefact Carpet V (Ring) >
Folded Artefact Carpet VI (Cobra) >
Folded Artefact Carpet VII (Idol) >
Isle of Destiny: Npc Raffael
Oracle Figurine