Hi sayedhamdani,
Both Dunlop and Talalay can be made in a “medium firmness”. What you personally describe as “medium” is of course the most important thing, and that can only be determined through your own personal testing. Dunlop will “firm up faster” than Talalay at a similar ILD (it has a higher compression modulus), but as your head isn’t too heavy, most pillows won’t use foams that are rated overall as quite “firm”, as compared to “firm” foams used in a mattress.
As for an “organic” pillow, you can look at the encasement material to see if that is GOTS certified organic, and then the latex to see if that is GOLS certified organic (the only GOLS certified latex at this time is in the Dunlop category), and then you could look to see if the entire finished pillow is GOTS certified.
In reality, most people that are looking for an “organic” mattress or materials are usually concerned more with “safety” than whether the materials have an actual organic certification and they usually aren’t aware that an organic certification isn’t the same thing as a safety certification. There is more information about the three different levels of organic certifications in post #2 here and some of the benefits of an organic certification in post #3 here and there is more about the different types of organic and safety certifications such as Oeko-tex, Eco-Institut, Greenguard Gold, C2C, and CertiPUR-US in post #2 here and more about some of the differences between organic and safety certifications in post #2 here and there are also some comments in post #42 here that can help you decide whether an organic certification is important to you for environmental, social, or personal reasons or whether a “safety” certification is enough.
While this site is mainly concerned with mattresses, there is a pillow thread here that you may find interesting.
As buttercupbetty mentioned (thanks butercupbetty!), many of the site members do offer pillows, but I’m sorry, I can’t act as a pillow concierge and go through each member’s site and determine for you which one is having a sale on which item. I’m sorry if you find it to be too time consuming, but that’s something you’d have to do for yourself, as the purpose of this site is to help provide you with the tool to determine “how” to make a good informed purchase, and not “what” to purchase.
I hope all of that information is helpful to you.
Phoenix