I am a lil bit late to reply here, well I also use herb vape and I customized it from an ecig-city coupon at Reecoupons because here all vaping stuff are much cheaper than other online stores thats why I prefer to buy from there if you need in future much once check there.
Why you are making it at home? I dont have any experience to make it at home, but I bought all vape accessories from ECig-City Coupons at Reecoupons, check there I hope it will help you.