Lots of variables that go into "cashflow" as everyones situation is different. 

There is so much variability here - that's what makes it tough Rental income is going to be taxed as ordinary income.

If it's going to be long term in nature, a fixed rate home equity loan is less risky than a variable rate HELOC.

Pets, service pets, subletting, furniture are important variables as well. 

There are tons of other variables such as level of rehab, size of the property, how competitive the local market is for flips, level of profit required, etc. 

A park like that will run at a 30-40% expense ratio, the biggest variable being how it is managed. 

@Dan Hedges if you have 3 or less properties total including a primary Pen Fed will put a LOC on any/all but if you have four including a primary they will ONLY lend on the primary, although on a Heloc backed by a primary they will go up to 90% LTV on a primary variable rate tied to prime + 1% or 85% LTV at prime + .5% or 80% LTV at prime.

That's a very loaded question and there are many variables to consider. 

Are the costs fixed or variable?

Each of these variables will dramatically change the advice I give the individual asking me this question.