you can bake with any pumpkin.
A sweeter pumpkin doesn't really matter much since most recipes made with pumpkin already use sugar.
Folks baked with any pumpkin for years and things turned out fine.
The pumpkins that really huge are actually squash and while you can bake with them too, they don't have much flavor as they have been bred for size not eating.
I think sugar pumpkins are just small pumpkins. They are sweeter than regular ones.
To make it sweeter just add a little more sugar or add honey.