If you could choose any company to design a new map/class/item.

I'd either go with Capcom and/or Atlus. Capcom for the use of the various sprite libraries to use as pets and/or gear. Rockman/Megaman gear and using any of the pet mecha from that series. I could also see them making a few Ghouls 'n' Ghosts sprites for warriors as well.Probably Atlus for access to the use of the entire Megami Tensei series amongst other properties they have as well. I wouldn't mind having Jack Frost as a little pet in the vein of the Jr. Reaper.