Hi thecatch,
The foundation post here and the posts it links to has more information about the types of foundations that work best with different types of mattresses. Post #10 here also has more of my thoughts about “wire grid” foundations when they are used with an “all latex” mattress.
While both of them would work well over the short or medium term and would probably work well over the longer term as well … the larger support surface of the wood slats would be my preference because it would probably work better over the longer term in terms of preventing the latex from sinking into the gaps.
Phoenix