R&R Textiles in Georgia has a 40 ounce maine grade carpet. It is the BEST you can get. Most are going to be 18-24 oz. Veada industries sells to alot of manufacturers but I think theirs is still 20 oz. I think they are in Chatsworth, GA. If you have any problem finding them, let me know and I will send you the number.
Thanks and good luck!