I will attempt to answer your questions in order
1. This is the Nub cooling moouthpiece Sold by Lamart of Switzerland
https://shop.lamart.ch/index.php?route=product/product&path=64&product_id=549 @funkyjunky ships VERY fast.
2. Vapefiend has an Eds T&T stem
https://vapefiend.co.uk/products/milaana-2-splinter-stem?_pos=4&_sid=5b0d11f30&_ss=r
3. I will suggest a DNA250C as the best mod type, but they are close to $100 and hard to find. I do have an Gen 3 Dual coming but I don'thave it yet. Reach out to
@bossman to answer this question.
4. Batteries you want 18650 flat top batteries I personally use the LG HG2 batteries for the most part. There are a lot of "fake" batteries so only buy from a well known source. There are some EU suggested sellers but you may need to search this thread to find the names.
5 If you mean extra glass mouthpieces I would suggest that you wait and see how you like the wood stem, the included stem and or the Nub before buying extra accessories.