Disclaimer
Before you decide to make this, I assumed you have your knowledge and know how to handle and manage the following. I would not responsible or any liability, money lost or money claim request because of this product or this product due

This is a simple design for the FPV, Most of the R/C control already using 2.4G as a standard. My project using the Futaba T9CHP, but replaced the RC TX module by corona 2.4G module. Together with the RC booster, By theory, you can control up to 6Km to 8Km. But I will do the field test and report. Any buddies who tried please update my page.

Here bellows is the BOM you need (the links I have no relationship with them, but you can have more details about what I am talking
1) Corona 2.4G TX module to insert in your Futaba TX. At the control rear side. If you have another 2.4G remote and the antenna is a male type (supposed should be) then is fine.
http://www.ebay.com/itm/Corona-2-4GHz-Radio-Control-System-8CH-Combo-for-Futaba-FHSS-DSSS-2-4G-/291143577816?pt=Radio_Control_Parts_Accessories&hash=item43c98270d8
2) The Antenna booster, you can bought this from the WEB. At present I can only see this manufacturing from Taiwan only. Normally this is for the people enhanced the WiFi power. Of course you can apply the same terminology for FPV
http://www.ebay.com/itm/2W-802-Brand-11b-g-150Mbps-WiFi-Wireless-WLAN-Booster-Amplifier-Repeater-2-4G-/201042238453?pt=US_Networking_Boosters_Extenders_Antennas&hash=item2ecf0d1bf5
3) WiFi antenna with extension cable (female / male), Or you can only necessary buy the extension cable, and keep using the original antenna, but Flat type can increase the gain per design. (need verify),
http://item.taobao.com/item.htm?spm=0.0.0.0.vLNBkG&id=10339403422
4) A tripod which is the common one for Camera. And together with the fast detach mount. This is convenient when you need to do maintenance on the unit.
5) A camera tripod mount, This is common nowadays for Go-pro and you should very easy to found this or you can use the old one and touch up a bit, and put it together with the glue. My photo show the mount together with the fast detach base fixed very well.
6) RC Lithium battery 7.4V (5400mAH); this is my battery mount 2 design thickness of the battery type. If you need to put the battery mount outside, and you can use the battery mount instead of battery mount 2.
7) A UBEC to supply the power to the booster, however, the unit of the booster need a bit larger power. So you need at least 3A and my case using the following
http://www.ebay.com/itm/RC-Plane-Aircraft-TURNIGY-3A-UBEC-w-Noise-Reduction-/151297348792?pt=UK_ToysGames_RadioControlled_JN&hash=item233a0654b8
8) A round type switch and some screws for battery mount, booster. Of course, you need some self tapping screws fix the left and right compartment together. However, my case using the tape temporary fix this issue. This is good for my fine tuning
4pcs M3X12 and nuts for booster and the battery mount.
6pcs M2 6X4 self tapping screws ; for the left and right compartment fixing