Hi wesleylaine,
Thanks for the kind words 
I think that the choice between Talalay and Dunlop is primarily one of personal preference because they do have a different “feel” with Dunlop being a little less “responsive” or lively as well as getting firmer faster than Talalay. While this can make it more “supportive” in the sense that it can “stop” the heavier parts from sinking in quite as much … support and alignment are different and alignment is the real key and is based on how evenly you sink into a mattress.
Both have a variety of ILD’s available and are very “supportive” but in general Talalay has a softer “feel” to it even in the same ILD. Given your preferences and the information you have given … my tendency would be to go with Talalay (based on “feel”, softness, and ventilation/temperature regulation). Bear in mind though that while my own personal preference is Talalay … when my daughter went to buy a mattress recently she tested both and preferred Dunlop all the way through her mattress so this preference doesn’t necessarily run in families much less in the population at large
The first thing I would suggest is to sleep on the mattress “as is” first to see how you respond to it for the first few weeks. You may be surprised to find that you don’t need a topper at all. The 10000 has wool in the cover which would already add to temperature regulation and I would base my choice on your personal experience on the mattress which will give you a much better reference point for what if anything to add.
I am currently testing the LaNoodles and it is a very “fluffy” topper which is somewhat of a combination of a featherbed and latex in terms of feel and performance. It is surprisingly soft given how relatively thin it is and it’s great for adding a softer hand feel and a touch of extra softness without the risk of a thicker topper in terms of alignment. A wool topper will tend to be firmer and provide more localized pressure relief than overall pressure redistribution. Of course being shredded latex and using less latex material in the topper … it is also more ventilating than a solid latex layer which along with the organic cotton cover would translate into cooler sleeping for most people. The latex inside can also be re-arranged to either be even or have more latex in certain areas since it is “free flowing” inside the cover.
On the temperature control side however … wool will be more temperature regulating than latex because although latex is the most breathable of the foam categories … it is still a foam which is an insulating material, it’s just less insulating and more breathable than other foams which in turn means it tends to sleep cooler. Wool can also hold moisture inside the fiber which keeps it away from your body which in turn helps temperature control because higher humidity feels warmer than lower humidity against the skin. You can read a little more about some of the many factors involved in sleeping temperature in post #2 here.
So I would first sleep on the mattress for a few weeks to assess what if anything you need to adjust and then based on your experience of both softness/firmness (and pressure relief and alignment) and sleeping temperature I would choose any additional topper based on my actual experience.
I think that this would depend on both alignment and pressure relief because with a herniated disk it can be very important to have both pressure relief and to make sure you are sleeping in neutral alignment. While clearly sleeping out of alignment would not be a good idea with a herniated disc, it may also be sensitive to pressure if you were sleeping on a layer that was too firm which can also cause tossing and turning and “twisting” away from the pressure which also wouldn’t be good. The real answer would be “just enough” softness to relieve pressure without sacrificing support. I think that the 10000 is in the right ballpark for both but again I would use your own personal experience and any specific “symptoms” you experience after a reasonable adjustment period rather than any “theory” ahead of time to decide on what if anything you may need to add. Once you know which if any “symptoms” you want to deal with … then matching them to the specific qualities of different toppers is much easier.
Hope this helps
Phoenix