i don't think anyone is willing to part with their trigger and metal memories since the trigger magnum and metal shaft are very expensive so they went with candy toy/gashapon version for their sets and wants to keep them. your best bet is to either wait until cstoys ever restock but mr. s says it was a one time thing or wait for someone on ebay to put it up again.
someone on ebay was selling a metal one not too long ago. other than that, yahoo auction japan and middleman is your only other choice. if you're desperate for those two memories, i'd go with the middleman