I'd also look into a mini-split as well.

Trailer parks are a COMPLETLY different best in REI, on level of difference from SFR as Mini-Storage, it is truly that different.

I was thinking of putting  duel head mini splits in each unit as they do tenant turns and maximize rents. 

I ended up providing these tenants with a new mini-split air conditioner and new patio door.

We've had better luck doing higher quality work to get higher quality tenants for more money.We've turned $600 apartments into $1000 apartments by replacing the flooring and kitchen and adding a mini split.

@Joseph GozlanWe were thinking about a mini arcade as well. anyone has any experience with that?

I think too many rehabbers jumped on the bandwagon of 2-4 unit deconversions into mini-mansions on the north side. 

In January I bought a new truck (Tundra TRD Pro) and have been outfitting it for an overland rig (essentially an off-roading capable mini RV).

Think of a 4 bedroom home as almost being a mini 4-plex, I'm not sure exactly what your market rents are down there but if they are anything like up here on the Central Coast then you should be able to get between $600-850 per room!

Combine the above info, and you will have a mini-market analysis, that should give you the answers to both of your  questions.