Hi Chief,
The “natural” latex line gives you a choice between 100% natural Dunlop and blended Talalay.
The organic line has an organic cover and you have the option between 100% natural Dunlop or 100% natural Talalay. You can also request organic Dunlop for an additional cost. The main reason to choose this would be for those that prefer 100% natural Talalay since the Dunlop would be the same in both.
There is more about the different types and blends of latex in post #6 here.
They will also go over any specifics you may wish to know about their materials when you talk with them on the phone and a more detailed conversation (or at the very least an online chat) is one of the most important parts of any online mattress purchase anyway (see post #4 here).
Phoenix