Hi Nichole,
From the numbers you give two of the properties meet the 1% rule. Meaning that the rents are 1% or more of the value of the home. This does not necessarily mean you have a great deal immediately but it is a way to quickly analyze properties for potential. There are obviously a number of things to analyze besides just numbers when looking for properties.
Some of the things I would look for are.
-What kind of repairs have been done to the property recently (i.e. Roof, HVAC system, etc.)
-Could the 4bd/2ba possibly be split into a duplex?
-Are the rents around market value? Get online and see what other similar properties are renting for.
Last thing people use self directed IRA's all the time for real estate purchases. I would be extrememly careful with a 401k loan. Because if you leave your current employer or fired the balance will be due immediately on that loan. I wouldnt want to be stuck with an employer because I owed them a debt.