I'm currently planning on building a Ranger(lvl9/10)/Shadowdancer(lvl10). Since the Shadowdancer has no backstabing ability, there is little need to use small weapons. It might be smart however, to use Kukri's (higher chance to get a critical hit) to compensate for this lack of sneak attack. I could also use longswords to get extra damage, this way I would save a feat(Exotic weapons). Or I could just add another level of Rogue to my char. Also, what stats would be important for such a char? I've been told that I need a minimum of 11/12 Wisdom to be able to take the Shadowdancer prestige class, and that Intelligence is also a very important feat. Any advice would be welcome.

Just take a rogue with the martial weapons feat.

You can back stab with long swords no problem, and great swords are among the highest damage weapons in the game anyways. (and you cn't use a shield as a rogue in any case...)

You can switch to shadowdancer pretty durn quick from a pure rogue, because all the prerequisists are class skills for rogues.

I've never heard of this "backstab". Are you sure you're in the right forum?

Backstab = Sneak Attack