Bluetooth won’t work that far away, but one of the regular WiFi adapters should work. Which one works best just depends on the area and who else is competing for bandwidth. If you were to find an external WiFi router which has at least semi-directional antennas to start with, then this might be all you need. You won’t know without testing since WiFi is license free and you can’t predict interference.
Personally I would code some simple ethernet application. We don’t know anything about the nature of what is being accomplished (are there timestamps sensitive to a microsecond? is it ok to be off by a full second?), and so it is hard to suggest anything more. A question of how much latency is tolerated, how much reliability is required, how often (rephrased, bandwidth requirements) there will be a trigger, so on, could change “best methods”.
Generally speaking simple TCP and/or UDP applications are fast and easy to build.