The best diapers for overnight protection are Pampers Baby Dry or Pampers Cruisers diapers.
I have an 8 year old son that wears Pampers Cruisers size 7 for bed wetting.
He's a heavy wetter and we tried those goodnite underpants for him but they always leaked on him.
I convinced him to try Pampers Cruisers size 7 diapers for his bed wetting and they work great for him.
He actually seems very comfortable in them and hates to change out of the wet diaper in the morning so he'll come down, have his breakfast while wearing the Pampers Cruisers size 7 diaper and then eat his breakfast and then shower and get ready for school.
He also wears the Pampers Cruisers size 7 diapers when on road trips or outside the house when there's not a bathroom available.
My 8 year old son seems to love wearing his diapers and that's okay.
I always used Pampers diapers on him when he was a baby and they held up good overnight for him and I also use Pampers Baby Dry and pampers Cruisers on his brother and sister who are till in diapers full time right now.
Pampers and Huggies are very absorbent.
My Nephew who is 2 years old wears Gentle Steps diapers from Dollar General and they are cheaper than Pampers or Huggies and do well for him.