Regardless of which route I take (SFH or Multi), I plan to base my numbers off of the returns I would need to sustain a buy and hold investment.  

We share a number of things in common - I'm also an engineer by day, have most of my real-estate investment locally in buy/hold multi-family, and have a similar set of goals to those you articulated. 

I am in the MA area and looking to purchase multi families.

I have looked at loopnet.com, can anyone advise other sources on finding multi family units?

One of the pieces of work included was a complete rewiring of the house to remove the active knob & tube system.

I'm aiming to net $200 a month from each property, so I need 15 properties, so I can see myself running out of money pretty quickly.I've thought about looking at multi-family homes, but I have some experience with single-family homes, and hate to start a brand new learning curve.  

Interested in multi-family, in MA.

I'm looking at a duplex that is not zoned multi family in northeast?

Multi units appreciate lower.

I'm a new member looking for advice and guidance to get started investing in either SFR or multi-family.