Best IG Super-Heavy Tank build and other questions.

Thanks to this sub and the excellent suggestions made in my initial thread here I've decided to do a few 2000point armies, starting with a super-heavy tank centered IG build. As per the last thread, the goal is a competitive shooty army.

Now I'm trying to put together the IG list, and the number of options has me a bit overwhelmed. There are over 9 super heavy tanks to choose from, and I'm not sure what would be the most competitive choice. I've heard that since turrets no longer matter in 8th, the hull mounted guns have an advantage. I've also read that while normal IG super-heavy can be taken over by enemy psychers, forgeworld super-heavy are immune. Lastly I understand flamers are now very strong, overwatch makes charging the tanks (from any angle now) very tough, and that the tanks can fire at targest within 1in. This leads me to my two questions:

Question 1.) So trying to fit 2-3 of these super-heavies into a 2000point army, which variant/load-out would you choose to be most competitive?

Question 2.) What should the rest of the army be fleshed out with? I was thinking tank commander for orders and/or sgt harker and/or yarrick for re-rolls, and/or techpriests engineers for healing. Add in some Scions/Stormtroopers for objective control and backline harass. Am I missing anything? What else should be added?

I appreciate all suggestions!