Out of your options, I'd say O3 Speedport Black would probably be the most suitable. You obviously have a little bit of idea what kind of a racket you want, because loosely speaking all those rackets you proposed are in a similar category. Having said that, I can tell you that personally I find Wilson rackets a bit more solid, preferred by the more seasoned players; whereas Prince rackets tend to have a relatively comfortable response, preferred by some intermediate players. Actually, you can't go wrong with any of the above rackets (probably except KSix-Two), but I'd suggest the Speedport Black. It's a typical "tweener" racket. The O3 White Original is also a typical tweener, but since Prince has updated their technology from the round O3 holes to the more square Speedport, the Speedport holes must be better in some ways than the old original O3. I played with a few O3 rackets before, very comfortable, not with the best control (though control is probably not your first priority, otherwise you should go with KBlade 98) and the stringbed is quite lively (which can be a good thing). In a Speedport Black you can experiment between different holes, which gives you choices, go with the "ports" for comfort, or the more conventionally "holes" for better control.
You should play around with different string types and string tension, other than different rackets. You can get drastically different results with different strings and/or tensions with the same racket. I suggest trying Prince Syn Gut 16 or 17, which is very cheap and plays reasonably well, at mid tension first. And from there you know what you want, i.e. softer strings, harder strings, higher tension, lower tension.