Depends on your local radio frequency requirements,
For Australia, 5.8GHz for video, 2.4GHz for TX, 900Mhz for Telemetry is the best combo,
Look up US requirements or alternatives for these frequencies, I think 900Mhz there is swapped with 433Mhz
Circular Polarised antennas offer better clarity and range for video,
Built in screen is fine, depending on what kind of range you want, if it is long range, spec up the TX & RX consider a tracking patch antenna.
If its close range multi rotor, I would look on BEVRC or FOXTECH for FPV screens and RC mounts that should be fine...
the Emersion RC 600mw TX is pretty good,