Yeah, the "Greatest Hits" hits is the called the "Platinum Series" over here, it's great because they're usually a lot cheaper! ;o)
But the boxart on this one probably just looks different from yours because it's the European PAL version of the game, which has several features that the Japananese international version also has but the North-American NTSC version doesn't, like fighting the dark aeons (they're like superbosses!)
The Bonus DVD is just a video DVD (not a game DVD) so it has no new game content: it has some "making of" interviews, an art gallery, a music video of "Suteki da Ne" and trailers for Final Fantasy X and Kingdom Hearts.
The papercraft Lulu dolls I made are not too scale with this Lulu, no; they would have to be much too small to build I'm afraid... ;o)
Lulu is about 34 cm tall and the dolls about 19 cm.