Newt would be better as Chief of Staff, although he also comes with some baggage
Ernst possible but not much name recognition or congressional experience and I think the VP he chooses needs to be well versed in congressional ropes to skip and ropes to jump to fight off both parties in congress and get an agenda passed.
Love Sessions, but I think it creates an easy narrative of two old white guys. Besides, I'm thinking we need to keep as many non-establishment R's in the senate as possible.
By process of elimination I think it will be Pence but I am not part of Trump's inner circle.
He could go rogue and pick Duncan Hunter the younger or -gasp - Cruz but I doubt it highly. As far as Palin is concerned, I simply don't think she is willing to put herself and her family through that media assault again.
Even if they were on good terms, he would not pick a guy whom he has claimed is ineligible to be president. That would expose him as a hypocrite.