Depends on the year.
The newer Kawi 4 strokes are amazing, 2010+. They are fuel injected and and just get on it fast. So powerful. The older Kawi 2 strokes aren't as fast as the Yamaha. Yamaha 4 strokes, I don't like much. I wouldn't mind one, but I don't really like them.
2 strokes and 4 strokes have 2 different worlds of their own. 2 strokes are explosive while 4 strokes are as smooth as a sewing machine.
-2 strokes get all their power at high RPMs, normally around 4000-5000.
-4 strokes have much more bottom end, you don't have to constantly keep shifting.
-2 strokes are extremely light, 4 strokes are much heavier.
-4 strokes are difficult to maintain as a beginner, they have a lot more parts in them (valves, cam, etc).
-4 strokes have engine braking, 2 strokes have none. It's just easier on the 4 stroke in my mind.
4 strokes are WAY more expensive period. They are more expensive to buy, and rebuild. 2 strokes are easier to repair not having valves and a cam to worry about.
I would get a KX250F, 2011 or 2012. It's an amazing bike and nothing compares to it, except the Suzuki. If it was an older bike, I love 125 2 strokes. They are fun to ride, but I wouldn't race them.
Decide on which you like better. 4 strokes are really easy to ride, but 2 strokes are a blast to ride. 2 strokes are pretty snappy, and they are explosive, meaning they just take off. 4 strokes are smooth, they don't surprise with loads of power.
11 years riding and racing.