Saha is better at scoring goals out of nothing, so in that way he is 'creative'. He can score a goal with either foot from any distance or angle. But in terms of creating for others and contributing to the team Yak comes out on top all day long. He's a great passer with either foot, good with his back to goal and is very intelligent. Saha is very technical, but in deeper areas he has a tendency to hold onto the ball for too long and make the wrong decision.
As for Crouch, I think he's very capable but I wouldn't want to see him here, his size would give defenders the easy option to hoof the ball forward, even if he is far better with his feet, I don't want to see that happen, and his lack of mobility just wouldn't fit in here, we are already a slow team as it is, and he has little to no athleticism.
I think the best bet would be going for a versatile forward if Yakubu leaves, someone who can play wide and fill in upfront when needed. Maybe Remy is the man, I haven't seen anything of him to be honest, but from what I've heard, he fits the bill. I think Brownie's right though, if Yakubu does leave I can't see Pienaar sticking around, best mates and all that.