Hey John, welcome to Sac BP -- I'm a local broker and property manager, we manage 100+ Airbnb listings and generally recommend investing in Multifamily as opposed to Single-Family.

Multi Family is much more heavy on the income numbers.

Best part is NJ is not what its made out to be in terms of landlord friendly, the state gets portrayed as the entire state being bad when really most wacky laws are in the major cities and they apply to 5 units or more.  2-4 unit multi families fly below radar per say. 

Without having much info, I would need to know the financial situation of the 'close family' to determine a best approach.

See family, and do some skiing!

I have been thinking small office or retail (which I have experience in); larger multi family (10-20 unit), RV Storage, and have even thought about beach front hotel, or at least ocean view hotel.

Imagine if you had one single-family home.

Our family had a summer home that had an open metal roof over part of the patio, and when it rained everyone was uncomfortable with the noise level.

It’s a Single family home purchased for $250K with land value at $12K.

I recommend that Detroit market for single family turnkey rental properties.