If Zone 2 is really 51 ohms you could use that output. 300 ohms is a bit high for solid state but it will probably be OK.
Bear in mind that you can spend an arm and a leg for unbalanced interconnects made with exotic wire. Balanced interconnects don't need exotic wire, and might cost you less.
Bear in mind that you can spend an arm and a leg for unbalanced interconnects made with exotic wire. Balanced interconnects don't need exotic wire, and might cost you less.