Welcome! From Southern Colorado here. You have joined the best rabbit community available. Everyone is helpful, kind, understanding, and insightful. You will get answers from people who have experience.
Good Luck with the Tamuks. I wanted to do the same. So I went looking for them. No one in my area has any. The last I read, Texas A&M were not selling them any more. I read they were selling out the entire stock and ending the program. After reading that, I looked and looked and found something just as good, I hope. I have aquired a doe that is a purebred NZ White but looks like she is a Tamuk cross. She has a super long face, large body and huge ears. She is 1.5x bigger than the other NZs I have.
If you cannot get Tamuks, use other genetics that have bigger ears, and breed them in to your line. Select only breeders who have the traits you want, and keep selecting bigger and bugger ears until you get the size of a Tamuk's ear. You could use Giants, or look at the breeds Texas A&M used and try to see if you can breed your own line of giant eared rabbits.
Breeding rabbits is not like dogs and cats. It is okay to line breed, out cross, and even okay for limited inbreeding to get desired traits, or remove underdesired traits. From my NZ doe, I have two rabbits that have her large ears. I just bred her to my Blue Steel Tipped Chinchilla buck, and hoping for kits that have her larger traits, but the Chinchilla coloring. I plan to breed her son to my Chinchilla doe in a few months. She was just bred to my NZW buck for test breeding. So she will be with kits for the next 2 months, and get a month break before the pairing.
He is just as big as his mom, with large ears and a nice stocky frame. He is black with white ticking, and half Silver Fox. My American Chinchilla doe is also half Silver fox. I love rabbits too much, I ramble about my plans. I could start a cult of rabbit worshipers. I bet most of the members would be in this community.
Rabbits are fun, and the Rabbit Talk community is a great place for information, friendships, and people who are like minded.
Have fun, and good luck with your rabbit adventure. Keep us updated on your journey!