The understanding of aging, disease, and death is progressing slowly but a few centuries of research will likely make significant discoveries.
Of the remaining important things that money can buy, I think cryogenics is a very decent gamble.
Probably the most successful at this that I'm aware of (morality aside) are the IVF doctors who use their own sperm to impregnate women.
Some with many biological children from this. Results from a quick online search:
* https://en.wikipedia.org/wiki/Bertold_Wiesner
* https://edition.cnn.com/2019/02/14/europe/jan-karbaat-fertil...
Oh, this looks relevant too and suggests some other approaches. Harem's and/or being a king seem like winners for those so inclined:
https://en.wikipedia.org/wiki/List_of_people_with_the_most_c...