They also have 1% or greater interest on both checking and savings

It looks like there's no compact wider than 24mm, which it turns out I already have in a Fuji F500 I retired due to a couple of dust spots on the sensor.

We have the capacity to save around $4,000 a month or so from my paychecks and want to begin saving as much as possible for a future down payment on our first property.

If the heat is radiators from a boiler, you have to separate the supply piping and return piping for each unit, then you need the extra boilers as well; you might be able to re-gun the oil boiler with something like a Midco Economite to save some money on a boiler, assuming existing boiler is in good condition and not too oversized for the biggest rental unit.One thing to point out is that you will now have multiple burners.

***Renting in the area is thriving because people are unwilling to pay market value for a house, unable to save for a down payment or uneducated on the minimal cost barrier of entry to home ownership.

With this same property and an estimated rent at $1000 a month here are the numbers:Mortgage $485 (75k at 4.75 for 20 year amortization)Taxes $100 (This is a guess because I have no idea what they would be in your properties area)Insurance $50 (This is also a guess but I am basing it off of my own rentals)Property management at 10% $100 (This depends on if you will be managing it yourself or not)Capital expenses savings for repairs 10% $100Vacancy 10% $100Monthly cash flow = $65 (6% APR rate of return on your 13k left in the property).Now there are several variables in this example.  

As landlord I will check my insurance and add an umbrella policy just if the motivation is your house and your life savings after an accident. 

My goal is to buy and hold single and multi-family units as a form of "retirement".  

I want to try this but I'll have to save up for the attorney work and use it many times.

I'm looking at triplexes and quadplexes.I have 2k saved currently.