Really I think Gingrich or Christie were the better choices, I imagine Trump has his reasons for choosing Pence.
Gingrich and Christie are the same "make" as Trump and they would have been adding to the dysfunction and approving all Trump's decisions. I admit I like Newt because he has major experience in foreign policy and in dealing with a divided Congress but otherwise, they are like 2 peas in a pod.
Pence, on the other hand, was picked to do damage control for Trump. He has a huge job in front of him. I don't know if he will even survive until the election with all the damage control he's already had to do. I don't know much about him as I didn't do my research on him yet.