Having flown 3 of them, and flown as a passenger in the fourth (thats the 172) - I also urge you to go for the Warrior.
Have you seen all these aircraft? If you have then I'm suprised you are even considering the Katana! They are nasty, flimsy little machines compared to the likes of a PA-28 or a 172! They also have less ratings.
The C152 is a good old work horse, but very cramped and not much fun. They also suffer from poor visibility.
The C172 is nicer to fly, and feels like a bigger aircraft. But still suffers from the same poor visibility.
The Warrior, although not the best of the PA-28 family, still beats the rest by miles in my opinion. It is sturdy, and handles a lot more like a big aircraft (So I've been told - I've never flown anything bigger!).
When there are only two of you in the aircraft it's nice that you aren't shoulder to shoulder the whole way (like you are in the other 3). When there are 4 of you, you'll notice that it is still a very comfortable and able cruiser.
If the cost does not vary greatly, and you can afford it, certainly pick one of the 4 seaters. Which one you do pick is, IMHO, a matter of personal taste (High wing v's low wing, Cessna v's Piper etc...) but I know for certain that if it was me, it would be the Warrior every time.
Good luck, and let us know your choice!
FJW.
PS: Having completed the majority of my PPL on the Warrior - i.e. a 4 seater, it is a point well worth remembering that if you pair up with a buddy, you will be able to sit in the back for each others flights to act as revision/forward teaching.
I have completed many hours as a passenger in the back of a Warior watching and learning. It is surprising what I have learnt whilst being able to concentrate solely on what is being taught in the front whilst letting someone else actually fly the thing! (You can then make notes, diagrams etc...)
The bottom line is, pick one of the 4 seaters, you'd be mad to go for a 2 seater if you can afford more!