I'm doing some preliminary research and I feel like we need at least one more rental to have the extra cash flow in order to help pay for the recurring costs.

Non recurring.

Some provide hourly consulting, some provide ongoing advisory support on a recurring monthly fee model, some provide both. 

RM has recurring monthly fees per user and I believe the upfront cost is more (although I'm not certain as I wasn't the one who paid the bill for it...)RM does have cool online features so you can pull up tenant info and work order history from a smartphone.

So sending these recurring mailers will help build a relationship with the recipients and they'll recognize your name, so when the time comes for them to sell, they'll have your name in mind.Adding the option to subscribe to an email newsletter once they are on the website is helpful also!

Even better, they set up an electronic monthly recurring transfer for rent payment.

Ultimately your mindset should be “what property will cash flow the best” not “do I want to live in this property.”Determining ExpensesI break these into initial expenses (one time costs associated with buying and fixing up the property) and monthly expenses (recurring costs associated with operating the property).

A Commercial lender or a local bank may not see it the same way but it can be nearly assured that a lender who sells a loan to Fannie Mae, Freddie Mac, or Ginnae Mae will be using the below to determine contingent liabilities: (copy & paste FNMA guide)Co-Signed LoansWhen a borrower co-signs for a loan to enable another party (the primary obligor) to obtaincredit—but is not the party who is actually repaying the debt—the borrower has a contingentliability.The liability does not need to be considered as part of the borrower’s recurring monthly debtobligations if the lender can verify a history of documented payments on the co-signed debt bythe primary obligor and ascertain that there is not a history of delinquent payments for that debt(since this could be an indication that the co-signer might have to assume the obligation at somepoint in the future).Generally, the primary obligor should have been making payments on the debt for at least 12months (although shorter payment histories may be considered on a case-by-case basis).The liability does need to be considered as part of the borrower’s recurring monthly debtobligations if:• payment by the primary obligor cannot be sufficiently documented,• a sufficient payment history has not been established for the debt, or• the primary obligor has a history of being delinquent in making payments on the debt.

Take a hard look at your income after taxes, and create a budget that defines how much you can spend after your recurring expenses (auto loan). keep to that budget and don't allow yourself to go over no matter what).

I believe there is a recurring payment option.