If the flip was a luxury home build that took a long time due to permits, weather, and other issues it wouldn't matter that it took 1-2 years.

I learned that you cannot trust every contractor you meet, and that patience is a virtue in the real estate industry.

The luxury market of San Francisco is also known as a boom and bust cyclical market. 

People will literally pay more to take care of less (newer, more "luxurious").We would definitely be buying this home to live in - what did you mean by "house hack a multi-family property"?

A lot of threads on this topic recommend Allure Luxury Vinyl Plank from Home Depot.

Although I know a few class A luxury apartment complexes that offer Section 8 type programs.

1-bed apartment building unit won't be $800 unless it's really fancy.Downtown luxury rentals are exception but it's a different market.However, you still will feel the difference between $3-4K rentals and $800's - PM will be much more time consuming. 

How about a good luxury house hack?

So I am searching for financing for a Duplex i am interested in and found Luxury Mortgage.

(being a union ironworker i have the luxury of being able to do this down the road if I choose)I currently have - 4plex that I bought two years ago.