There are several books about "Al-Sīra al-Nabawiyya" which are his biographies.
What is more interesting and quite unique is the inclusion of the "isnads" which are the chains of transmissions.
We can say that his existence is proven by 1) the influence he had and still has on so many people throughout the ages and 2) the rigor by which his teaching and "Sunnah" have been collected and transmitted (at least up to a certain point of time).
However, I have my suspicion about the so called authenticity and even Divine protection from alteration of the hadith books like Sahih al-Bukhari or Sahih Muslim in particular and any of the 9 books of the " Al-Mu’jamul Mufahras li Alfadhil Hadithin Nabawi " ( 1. Sahih Bukhari, 2. Sahih Muslim, 3. Sunan Nasai, 4. Sunan Abi Dawud, 5. Sunan Tirmidhi, 6. Sunan Ibn Majah, 7. Muwatta Imam Malik, 8. Sunan Darimi, 9. Musnad Ahmad.) in general. Indeed, I've always wanted a PDF copy of at least one of those books original manuscripts esp from the Abbassid era (or at least from the early Ottoman era) as a source material of study but I've never found one, I'm sure they exist though. I think that a lot of Hadith book of the modern era are approved copies from whomever has their copyright so to speak. There is no doubt in my mind that a lot of the hadith (Including books like the so called "Sahih" al-Bukhari ) have been made up and/or forged throughout history and the ambitions of Islamic rulers. Also, I'm not a hadith specialist as I preferred to study "Fiqh" according to the four schools when I still was interested in all those religion stuff (I was agnostic at the time but curious to learn now I am just a non-believer Muslim).
I would add that in Islam the cult of the prophet is a fact even if it's a heresy to say such a thing. Indeed, Muslim are supposed to love him more than anybody in the existence even more than their mother, father, children and even own self. It's difficult to love someone you don't know and who lived almost 1500 years ago with such devotion, only fanatics can convince themselves that that such thing is even possible. In fact such love for the prophet is a condition to the "believer" (faith) status (which is above the status of Muslim) according to this famous hadith.
I mean, same goes for Jesus and other religious figure like Elvis Presley... Furthermore, Muslims are supposed to aspire to be as close to his sunnah as possible i.e pray like him, sleep like him, eat like him, drink like him, dress like him, walk like him etc... I mean if that's not a cult of personality I wonder what that is ! Also he had some conjugal privileges according to this verse of the Holly Quran ! May the peace and blessings of Allah be upon him !!
As for his type, I think EIE is a good fit.