"Can anybody tell me the diffrence between all these new plastic cats from Hobie, they all look the same to me:
Twixxy
Wave
Teddy
Dragoon"

Hi There, my opinion : don`t go for any of these boats, from what you describe your needs as.
The Hobie 16 will suit your needs, but only just, so it is the minimum spec / size of boat you should get. We have 2 sailors at our club that sometimes sail Hobie 16 together at 180-190kg. They are heavy for the boat, but it sails fine (and they have added the spinnaker kit), just realize that the limit will be in less wind than with optimum crew weight, 130-150kg. So it will suit you & your girlfriend fine. Not a great boat for single-handing in strong wind, again, recognize the limitations, carry a righting aid of some sort as well as righting lines & you will be fine. Out of what you say is available in your country it is the best option.
And regarding pitchpole tendencies : Once you have mastered the technique of sailing it in strong wind it is a very exciting boat to sail. The crew needs to have lightning reflexes in depowering the jib as it is a powerful sail, if this is done correctly, 30 knots is still sailable on a Hobie16. Pitchpoling is part of cat-sailing, as is capsizing & righting the boat. Learn to have fun with it.
The Hobie 16 also gives a dryer ride than many of the newer design cats because of the raised trampoline.

I don`t sail a Hobie, but have crewed on them for 4 years in all sorts of conditions, and have come home from a 55knot storm. There`s not a lot wrong with a Hobie 16, despite what some people say.

Cheers
Steve