BFH, sawzall, portable table saw, 12" compound sliding chop saw. wet tile saw, multiple drills, pry bars, portable compressor, Every imaginable small hand tool.

You will need some lighting , portable restrooms , water would be nice , gravel for parking areas , tables .

This may involve adding ductwork, installing a separate HVAC unit, or using portable heating and cooling units.Electrical: Another important consideration is the electrical and plumbing systems.

Quote from @Hector Serna: Quote from @Max Feinberg: @Hector Serna sounds like some of these things could be resolved/noticed before actually getting under contract  Looking for adviceThank you though For properties where the utilities are off, this can help you discover potential plumbing issues:At the home improvement stores, you should be able to find the fittings to make an adapter for connecting an air pressure tank or portable compressor to a hose bibb.

I like the new portable stove, it makes really efficient use of space esp for kitchen.

Also, portable AC units and window units jack up your utility bill in the summer, and those can sometimes fry the outlets since they draw a ton of power compared to central AC. 

Currently I work at a small company that underwrites lease purchases on portable buildings and cabins.

Simplisafe makes a great PORTABLE alarm system for the vacant houses..

2 ways... quicken property management. it's like excel, but presented better. tons of features and a cake compared to quickbooksreceipts - a portable scanner... everything gets filed in special hard drive under year, month, $xx - place of business - date. this way i can find every receipt in 2.6 seconds.

Cost and portability are not important.