Sokoban items are arguably the current "best in slot" equipment for players throughout Wyvern, despite their race or guild. There are currently three variants of Sokoban items: blue, red, and gold; the differences between the colors relate to the number of times they can be slotted at an Upgrade Station.
For the status of Sokoban defensive gear (including wings, ring and amulet), check the page on optimal Armor. Same for sokoban weapons, on the optimal Weapons page. On both, press ctrl+f and search for Sokoban.