Still searching a good one with pos mining with a good dev / history , theexchange are for now the only solution as webwalelt with the right security : bittrex , yobit and some other . As solution i can make an asset on Omni or XCP to give more stability and decentralized exchange right away to Metal coin , but i know is possible to build a system counterparty like still on the actual metalcoin chain as i'm testing , and with a webwallet like this one : https://sogparty.com/BETA/#
with asset creation and decentralized exchange buit in