Going with a bigger wont solver your problem, it will make it worse. If you are shooting for this event, I'd keep the current turbo and try if the rolling antilag will help you.
Did you try brake boosting? It's usually used a lot with roll racing to get the boost up before the race begins, could have helped you. But 3300rpm sounds a little low rpm to get it going even with brake boosting in a 67mm.
To get more torque, you need to up the boost as more boost creates more torque. Torques is nice to a point, but it's actually the power that makes the car accelerate faster, not torque. That's why you have gears in your car. But to get more torque down low that you are ultimately asking for, you need a smaller turbo, more displacement, nitrous or VVTi.
If the rolling antilag is not enough, I'd get a 50-75hp shot of nitrous and turn it off at 1 bar, or when you have enough boost to get the car going.