Personally ive been using the lvl 80 goldsmith item. Its 5 gathered mats from 4 zones(resin and mana sand from rak tika, ore from il mheg, sand from kholusia, and silver from south shroud - all of those but the resin are miner while resin is botonist). Not perfectly ideal, but the subcombine is same-class so no need to change between quick-synthing a bunch of mana nuggets and turning them into braziers.