I would suggest you go to this web site: bwdepot.com
It is very informative an should answer most if not all your questions. For pricing and more info, especially under the resource center tab, check out abswood.com. I build decks in Atlanta and have work with them several projects.
They are a hardwood specialist for decking. You will be constantly maintaining pt decks.

You being from Oklahoma and all,another site you could check out would be mine, www.deckmastersllc.com. All the decks over there are fairly close to OKC.

No matter how preasure treated wood is fastened or finished nothing can change the nature of PT pine it will splenter,crack,warp and split exposed to the sun. John

Build larger then 12x12. You will see a lot of people don;t use their decks and the reason is that 12x12 is just a tad small (there was a study once but I can not find it).

14x12 is even better - 12x12 seems to be a normal size but it is to small for normal use.