Wireless Ethernet bridge

Hi All, I need a wireless bridge solution that allows to pass jumbo frames over a distance of 3 miles, using the 5.8 GHz band. The original solution was a Proxim Tsunami GX 200, but unfortunately it doesn't go beyond an MTU of 1536 bytes: we need at least 1544 bytes, ideally between 4470 and 9212 bytes MTU. The handoff should be MM fiber, the desired throughput 200 Mbps. Thanks, Stefano