I've done a little bit of 2.4GHz amplification to increase our wifi signal at school. But the main thing I used was a powerful USB adapter, rather than an inline amplifier.
I would suggest, however, that you buy a high quality RP-SMA extension cable to go between the amplifier and the antenna. You can buy another short one to cut up and wire to your transmitter (it's coax, so strip the end and solder the signal wire where the antenna attaches on the TX and the shielding wire to the ground on the TX).
Here is a cheap extension cable:
http://www.ebay.com/itm/for-Wi-Fi-Ro...item27bb005be9
The problem is that the longer the cable is, the weaker the signal gets. I would also suggest buying a higher quality cable, like LMR400. You may have to solder your own ends on it.
http://www.ebay.com/itm/LMR400-25ft-...item4cf214462c
LMR195 would be better than that $3 cable too. Not sure how much performance difference there is between LMR400 and LMR195.
http://www.ebay.com/itm/50-ft-LMR195...item1c232a5864
Then you would want to put a good antenna on the end. You could use an omnidirectional antenna if you plan to fly in all directions. Or you could use a directional antenna if you only plan to go in one direction. I would suggest googling and building your own bi-quad or double bi-quad antenna if you want a directional one. I have built several and they seem to work well. But probably the best thing to use is a simple omnidirectional antenna like what comes on a wifi router. They are cheap on ebay.