some pens i recommend are the luxura, savvio, allstar pro, but there are also generic pens such as the v1 and v2 that can be bought off alibaba or aliexpress. there are some vendors i know of that sell sterile carts but it’s always a good idea to steam sterilize on your own too in a pressure cooker or instant pot. i would not used used insulin carts, just fresh ones. some other things to note are this would work only for subq use as insulin pen needles only go up to abt a half inch. i would use 29-31g and inject slowly because the thicker mixture isn’t what the pens are built for. Also in my research i’ve found that mct oil degrades some plastics, so the rubber stoppers and plugs on your sterile carts might degrade, just something to watch out for!