Pumpkin variety to make Jack O Lanterns?

Ok so I know Halloween has been and gone lol but I'm asking for next Halloween. I live in New Zealand and we don't have the orange skinned pumpkins at the supermarket. I found some seeds at a shop that are for a variety called Dills Atlantic Giant and the skin is orange. Can I use this type of pumpkin to make a Jack O Lantern if it doesn't grow too big? I was thinking of letting it grow to a certain size and then remove it. But I want to use the insides for a pumpkin pie... would it be ok? I have absolutely NO experience on growing pumpkins or any vegetable for that matter. What happens if you use a pumpkin before it has grown to full size? Does it still taste the same?