Hi sammie,
There is more information about choosing a topper in post #2 here and the topper guidelines it links to, and there are some topper guidelines in post #8 here that you can also use.
In case you haven’t already seen it, there’s more detail about featherbeds in this post. Featherbeds can be any combination of feathers and down, and depending upon the fill power, fill weight, and feather/down ratio, the comfort (and insulating factor) of the topper can be varied. This can add a small amount of warmth and extra surface plushness, and indeed you would want to “fluff up” the product frequently, and even rehydrate the down over time.
The type of breed used for the raw wool and the thickness and resilience of the wool fibers, the compression of the wool batts, the tufting or quilting of the topper, and the overall construction and layering of the topper along with the amount of wool inside will all affect the feel and performance of the wool topper, so I would suggest a conversation with any retailer or manufacturer you are considering to talk about a specific topper (wool or down) if you aren’t familiar with a specific topper. There is also more about wool toppers with some sources in post #3 here. Also look in post #8 here. Wool is among the best temperature regulating materials, but keep in mind that it regulates temperature in both directions (it’s used in the desert and also in cold climates because of this) so while it may not feel “cool” … it generally doesn’t feel “hot” either, but in thicker layers and higher concentrations it can have a more insulative impact. It also helps to regulate moisture and reduce the perception of temperature that comes from higher humidity levels (similar to how temperatures feel cooler on less humid days than they do on more humid days).
Overall, I don’t keep a detailed listing of all the suppliers of various types of toppers, as that would be much too large of a task to maintain in an ever-changing environment. But hopefully some of the information and links to various providers I’ve provided will help to give you a good start.
Phoenix