I keep my number of guests low to try and keep the headaches and bad reviews to a minimum.

unless your in a low end tweaker park.

@Ryan Keenan If the home is in a condition where it can be conventionally financed I do not think you will have trouble finding a bank that will do a 25% low balance loan.

Your FICO score going to really low if you use any personal credit cards (or your company credit for that matter) and you won't get offers 0% until you pay it off

I really don’t want to because they cash flow well and have been low worries.

That seems really low

I am also considering to go to Home Depot or Lows to get familiar with costs of material by myself and also get contacts of various contractors or handymans from my area so that I can just quick give them a call later and find out potential cost by discribing situations.

Assuming your credit is good, you have the required down payment, you income qualify, etc, for an investment property the rates should be in the low-to-mid 5's for a 30 year fixed for a 1-4 unit residential property. 

@Darrick Lowe who says HELOC rates are lower if it is a rental?

Low-cost index funds in your desired asset allocation.  4% withdrawal rate.