Leverage: Are we doing it right?

[Account Closed]

My wife and I own a couple of properties in Los Angeles (1 single family, 1 4-plex). After many, many discussions, we've decided to use our resources and move forward in expanding our long term portfolio and purchase another multi-unit property. Our plan is as follows:

Property 1, single family home: Where we live now. Currently sitting on about 350K in equity. Just signed docs for a $170k line of credit at 4%.

Property 2, 4-plex: This building was purchased 12 years ago and has provided us with a very healthy stream of monthly cash flow. Sitting on about $400k in equity. Rate is now at 6%. We're currently trying to do a cash-out refinance at 5.125% (non-owner occupied). Hoping to get somewhere between $170-200k cash out. This would shave around $3-500 a month off our cash flow from this building.

We'll then use the cash out and part of the HELOC to purchase a new building. We've discussed more expensive buildings with less units in more desirable, rent-controlled areas.... and 5+ unit buildings in non-rent controlled, less desirable areas. Our agent, who is my wife's father is exploring several options for us. I personally like the idea of finding a multi-unit fixer and perhaps starting fresh with new tenants (our single family home was a major fixer and it worked out very well for us).

We will also use a portion of the HELOC for flipping to bring in extra cash flow.

We in the ballpark here?