[World Editing] Need help at editing and creating new areas for 4.x.x

[Badcobra10]

Greetings,

I'm here, once again, asking for your help.

I've tried to find a tutorial for 4.1.0 / 4.0.6 but I've found nothing: Not a tutorial nor the programs to do the editing. I've tried lots of different 'tools' but none of them seems to work (they crash or just doesn't even load up).
I made a decidion that I want to model edit instead of doing everything with the gameobjects inside WoW. The reason to do that is because I cannot see the gameobjects from far.

In fact I would like to create a new world/area.

Thanks.


EDIT: I got a idea but I have no idea if it works... But let me tell: If I make a new area in wotlk client, would I be able to use it in cataclysm too? I mean that I would just add the .mpq file to /data folder.