On a 450 , maybe 1 . 3 ghz video , but the antennas get really large at that freq , I would go with 2 . 4 and diversity VRx . Use a minim OSD . Open pilot doesn ' t do GPS very well at all , and you are going to want GPS for RTH when you go out of video range . Pixhawkapm has acro mode , aka rate , mode . html , so you can fly it like a racer , and flip it in to return to home mode when you loose link . Pick from any of the pix . or . hawk type varients , like pixracer , or pixhackpixraptor . Get a TBS crossfire , you will have range of over 14 miles on control . With TBS crossfire it can also sendrecive mavlink telemetry . So not only will you have telem data over your OSD , but if you loose video , you can look down at your phone , laptop , and see where the craft is in real time laid over google maps , and send it commands . If TBS crossfire is too much $, you could go with any of the 433 mhz control systems , but loose telemetry over that connection , so you would need to get a 900 mhz telem , and I think that I read that 900 mhz and 433 mhz can conflict , something about harmonics . TBS crossfire is worth it . With this setup , in the right areas , you will probably find your limit on range is battery power .