Yes, it will carry 1kg of payload, it will fly, (very fast) and as Mike says would probably not last that long, there are other airframes that would be a better choice. The main thing to look for is wing area if available.
1kg is quite a lot to carry, plus battery, motor etc.
I am about to finish a Reaper build -- what a toad. Do Not Buy.
I am not the model owner but got interested in the project after the owner gave up on it due to quality issues.
Any of the 'real drone' models are just for semi scale look, not UAV use or experimentation. There are several YouTube videos where the wing fails in flight. NightFlyer Dave did get one in the air and landed safely.
As Michael Pursifull says, it is a very bad choice.
Heavy and small wing area = fast, otherwise it will stall and crash.
Not last long because you have to fly it fast, which is not easy and you will have to try fly slow to land.
Another good choice for 1kg payload: http://www.bananahobby.com/5-ch-blitzrcworks-super-sky-surfer-rc-sa...
Flying weight is total weight of aircraft ready to fly including everything, eg battery, motor, ESC, servo's, etc but without...
...Payload, is the extra weight an airframe can carry comfortably eg camera, OSD, video transmitter etc.
A plane with a flying weight of 2kg probably should be able to carry 500g payload but it depends if the plane is overweight to start with.
A Boeing 747 can carry 100+ tons payload but a Cessna 182 can only carry a few 100kg. The 747 has lots of power and flies really fast.
thanks alot, you saved me days by providing very useful info.
please suggest me an airframe, with landing gear / wheel similar to predator airframe. because i want to attach my boscam hd19 camera beneath the cockpit just like real drones.