I hate to be the wet blanket in this, and I really do empathize with the emotional difficulties, but it's really not a good idea IMO.
As marymc points out correctly, anything can happen in life and finding a young partners is no guarantee of future health at all. But this is a case where the vagaries of life will only be an added risk to the absolute guarantee of aging.
The average life expectancy of an American male 75.5. So you can plan on 20 years. You will then be in your mid 40's. That is really not a good time to be looking for a life partner. I don't have the stats, but I have heard that women over 40 have a dramatically harder time finding partners then those in their 30's. The data was based primarily on divorced women which no doubt plays into the results.
So after 20 years there is a decent chance he has died or his health is failing and either he and or/you may wish he was dead. Do not look around at 75 year old guys to assess this because the ones you will see are the ones that are not in hospital, hospice, home care, etc.
On the bright side, if he is generally healthy, you got 20 decent years. Many people do fine and then basically fall of the edge of a cliff rather than taking the slow route. But modern medicine has made that less and less likely. There is a decent chance you will spend at least a few years in hospitals as modern western medicine seeks to torture a few last years out of him.
It is very hard to be logical when your emotions are strong, but health is only one aspect of the strains. being different ages will present all kind of relationship challenges. Was he married before, does he have kids, is he financially well enough off to retire, what happens when he retires and is kicking around the house, etc?
People like to say that "life is short". The truth is life is NOT short, it is very long. In fact you can take all the sayings: life is short do this or that and change it to life is long do this or that - you will find it works just as well.
I'm just a little younger than him and I can tell you that you may be "full of life" but biology is such that stuff is beginning to wear out - eyes, memory, metabolism, skin, etc. It's not bad if you are with someone in the same condition but a contrast is not flattering. At my age it is not uncommon to have bursts of energy and enthusisam (esp. if a young woman is involved) but it is hard to sustain (no double entendre intended).
Given the volume of this post, I won't even delve into the myriad complications of having young children and having him die while they are in high school. Of course you could use Saul Bellow as an example and just jump right in.
There are plenty of cases where this kind of age difference has worked out (although this one is pretty extreme) so it could be great, but not calculating the expected outcome would be ill advised and, I fear, too soon regretted.