n33 rocks - heavy. It's in the upper 80 grams with a lot of it's weight around the head. I can't remember if it's very stiff, but I hated it for doubles. It was too heavy to handle. However for singles it was not bad, but I would argue it is outclassed by the woods 80, 90, etc.
n50 flame - aesthetically awesome racket. I don't know why they had to butcher it for the second generation. This racket has a (personally) fantastic balance between weight, head heaviness, power and feel. I (again, personally) loved this racket for doubles. It was neither too light for hard smashing, nor too heavy for driving and defense. If your cousin is into mostly doubles then I would highly recommend the 50 over the 33. I can't imagine him/her being remotely disappointed. For singles, I would again consider looking into the Woods series, which I believe are a bit more flexible and head heavy which lends them greater power with less force used (but you cannot "crank" the racket for a hard smash like you can with a stiffer racket).
If you have a website where you intend to buy either one of the rackets, I'd love to know about it. I'm having a tough time finding the first generation.
It's impossible in Canada I think. I bought the last n55 at max sports and I can't find another. Depending on what you're looking for badmintonalley.com has a few first gens but shipping to Canada is pretty expensive from them.