1GB downstream without PPPoE and stock FW (OpenWRT barrier breaker) is ok,
But as @slh said, all together, I doubt it.
I guess even the newer TP-Link M707 (MT7981), which is 3-times the prices, will not be able to achieve this.
Read this please: so-you-have-500mbps-1gbps-fiber-and-need-a-router-read-this-first