Hi welshie,
Post #2 here has more information about the differences between blended talalay and 100% natural Talalay but Shawn is right that in practical terms they are functionally more similar than different and differences in design and layering would make a bigger difference than the differences in the material itself. SleepEz offers both but of course the 100% natural Talalay is more costly than the bend.
That would depend on the likelihood of “accidents” and the importance of waterproof vs water resistant and your budget. Post #89 here has more information about some of the differences and tradeoffs between different types of mattress protectors. If “waterproof” is most important to you then the thinner membrane type would probably be the best choice even though they are less breathable and may affect sleeping temperature.
Phoenix