Depends on the property honestly. 

With your brother’s $50K equity already in the property, this should make the loan-to-value ratio favorable for refinancing.HELOC monthly payment on $68K: ~$300 (depends on your rate and term).Lease payment from brother: $800/month.Future mortgage (refinance $68K over 30 years at 6%): ~$400/month

If I choose to rent, I might make around $200 - $500 a month.

If the $700K sales price is not used correctly to acquire qualified real estate, the exchange could fail, triggering tax liability.Future exchanges will depend on the total value of the replacement property acquired, so entering syndications could limit flexibility.

it's going to vary depending on the market and what you're looking for to meet your goals. 

The implication is your ex-wife cannot simply choose to stay beyond a 60 day notice.  

Without population growth, your rental income will lag behind inflation, requiring you to find additional sources of income.How long your rental income lasts depends on the job growth in the investment city.Non-government jobs are inherently temporary.

@Brice Alef-Torrisi putting each property in its own LLC is usually overkill.Getting a bank account for each LLC is typically something you need to do to avoid "piercing of the LLC corporate veil" (actually depends on tax selection you made for LLC), but is also overkill.You haven't indicated how you are holding the deed for the latest property.If in your name or same LLC, you don't need a separate bank account.If in separate LLC, you can create a Master LLC, have each property LLC hire the Master LLC to manage their affairs, and just get a bank account for Master LLC.This is an opinion, not advice, so lookup CPA Frank Alcini in Troy for expert advice.

The tax treatment in such cases may vary depending on specific circumstances.

Depending on the seller, you may sweeten the deal, by letting them know that they don't immediately need to cash out, or can partly cash out.