I'm working on a high school electric vehicle project. We would like to transmit UART data from our Cycle Analyst (Grin Technologies) to a trackside laptop, probably maximum 1km, mostly line-of-sight but not guaranteed as the car goes around curves, etc. We can use an Arduino to format the data and add checksum, etc.
What's the best RF transmitting option for UART data in this circumstance? I was looking at xbee ~60mW with external antenna, but it requires a lot of research for 802.15.4, mesh, multi, etc. What am I looking for?