There are alot of factors to consider when doing FPV. The first thing you want to remember, is don't go overboard and spend more than you want to lose. Atmospheric conditions change, and radio wave propagation changes along with it. Signal quality changes day to day. Start off small, and extend your range from there. I personally have a 500mw 900mhz video tx, and have been up to 5000 ft with no loss in video quality. I was, however, using a 72 mhz RC TX. 2.4 is a little sketchy on the range, and I have had days where I could fly out to 3000 ft, and days where I could fly out to less than that. Do some research, and look at the different combos that people are using. I would highly recommend buying something from a USA dealer in the event that you have an issue with the TX or RX. On a side note, I have a Diversity setup and my quad is fitted with the 500mw system and a Spektrum park flyer receiver, and I regularly fly to over 1000 ft. This is with a Park Flyer type receiver. i have the video Transmitter fitted with a Low-Pass filter though to avoid problems with the 2.4 RX
