GMRS Yagi Antenna for 70CM UHF Dual Band 400-470Mhz Ham Walkie with High Gain 7DBI Outdoor Antenna for Ham Radio Transceiver Repeater SL16 Female Connector UHF Mobile FM Scanner

You can buy a high gain yagi antenna of decent quality on amazon for $40. Up 5 feet atop a roof gable with a 25 watt input should easily make 8 miles if the path is relatively flat (no mountains). I run one of these on gmrs here. https://www.amazon.com/GTOMNI-400-470Mhz-Vertical-Repeater-Connector/dp/B0DNQ8HVH8