My friend Dylan Marma would be a solid bet and I'd be happy to make an intro.Using leverage to scale, such as borrowing against this cash for larger down payments?

Do you need or want monthly cashflow, tax write-offs, betting on appreciation,....   

That’s the best bet.

An experienced broker with lots of choices at the palm of their hand is probably the best bet.

I’m not a betting man.

Wishing - betting death on your tenants?

I bet if converted BACK, it would be 4br+, probably a rather spacious 4br+: - a whole lot easier to rent given much more demand for such vs efficiency or 1brs- no longer competing in any way against apartments- no more utility issues, because tenants cover 100% of there own utilaties- no more headaches of wrangling different persons to play nice togetherAnd on and on and on...... 

Well the bet I'm making here is that CapEx and repairs will be very low the first few years (honestly event he first decade), and once all the construction ends I will be able to increase my rent closer to market rent at $2k which will give me a better cushion.

Airbnb gives you the best bet at getting both. 

Quote from @Brandon Foster: Hello Ryan,STR is do able in the north county area but there are a lot of rules and regulations.The city of Oceanside right now will not allow anything STR unless it’s west of pacific coast hwy.This is changing a lot too so you need to be aware of that in your plans.Carlsbad is super strict too but there are some condos that are still available to do STR in.Medium term rentals are as safer bet but way less profitable.