All the games are virtually the same, with slightly different grpahics. The 'has more Legendares' is a silly idea, all the games have all of the Pokemon programmed into them already. Personally, I would go fo FireRed, because it is the most basic storywise, because it is a remake of a basic game. This means you don't have to bother with the truck, as mentioned before, and any other flags and whatnot.