You will attract more tenants and more rent by providing laundry hookups or machines, especially in a single family. 

It produces the best cash on cash return you can find.

If it’s a low end property in a poor neighborhood with lower end rents, then yes, you’re going to attract lower quality tenants, potentially high turnover, and it’s not worth it.

At the end of this you'd have a better placed portfolio ready to grow and produce NOI. 

Is a spot with a lot of rentals available considered a good spot?  OR is a spot with little/no rentals better because you don't have as much competition?  The spot I'm looking at with little/no rentals available is on...

Or work differently so you produce a greater income and can buy all cash (or pay down debt so you can get a conventional mortgage)in your question I hear you wanting to be creative, which is awesome - however creative in looking for money means you may want to go where there is money?  

Any suggestions on what type of content will attract investors?

I can't produce more inventory all on my own.

If you're thinking about buying a mobile home, one of the things you need to know is the neighborhood and types of clientele it attracts.

It looks like you take a cash flow loss in the beginning, but potential for appreciation and loan amortization make it possibly attractive in the long-term, if market growth persists.