ETXTtomato,
I'm by no means an expert on the subject.
I'm trying to grow a couple of Atlantic Giant plants this year. Most of my knowledge has come from reading "How To Grow World Class Giant Pumpkins, vols. II and III", by Don Langevin.
Many people obtain their seeds by requesting it from the grower, or trading seed with the grower, or others.
I got seed this year from The Dill's website. It came from a 655 lb. pumpkin.
I also ordered seed from Don Langevin's website. The seed I received is from Langevin 953 X Weir 1260.
I'm trying to grow one plant of each of these.
As for a certain strains being better for southern states, I don't know regarding this. If you are trying to grow over 200 lbs., it seems that the genetics of the Atlantic Giant will give you your best shot at this, in a pumpkin.
I don't know if you've read my reply to your in the post on 'how to grow the AG round' I posted some additional info.
Best wishes to you!

Douglas

hi! I'm finding seeds of giants pumpkins please if somebody know someone please send me a e-mail to maru_ariasg@hotmail.com please
thanks!

maru_fallen_angel :do you mean, you are looking for seeds to giants pumpkins.
If someone knows a Giant Pumpkin grower. Pleae email you at maru_ariasg@hotmail.com

I am trying to find gramma seeds preferably Maltese Gramma.
if you can help email rowdy_roddy_au@yahoo.com.au