Sell or hold when trying to grow?

Hello, have a doublewide house that is paid off currently worth $230k and renting at $1600 per month. The cash flow is nice but it is difficult to find a lender that will do a HELOC or even conventional financing to grow.

I’m considerIng selling this property and seeking opinions on how to best use the cash. 
I could purchase a duplex for ~$250k and $1000 per side increasing my gross revenue by $400. Then HELOC this property.

There is 3 duplex’s for sale at $235k I could put 20% down on each and buy all three. 

Considering buying land in town and building 2 modular duplexes or triplexes to avoid sprinkler systems. Most expensive option but should create the most equity. 

Or purchase a larger multifamily ~$1M 

Not considering BRRR at this time.