I guess you mean "buy"
buying a harness for someone else is tricky...remember, a harness is the connection between the power of the kite an the rider.
It has to sit perfectly, and everyone is different.
e.g.: if you are a friend of mine, and you buy me a waist harness, I could ride 1 hour and then I cannot move anymore...
Or you buy me a seat harness, my back would be ok, but I cannot do my tricks.
So, the point is, you can go wrong easily.
I suggest you get a gift certificate, and your friend selects the one he needs by going to a shop, putting it on and test it under load.
just my 2 cents...