If it were me and the wood is in good shape, I'd sand off the latex and use a high quality wood deck oil stain. Let it soak up all the oil stain it can hold. Then every season, apply more oil stain and let it soak in.
It's been my experience that any topical coating like paint, only TRAPS moisture in since it would be impossible to make a painted piece of wood water proof.
If the wood is rotted out, then replacing it with a non-wood product, like the new deck materials out there, would be a better option than just replacing it with wood again.