If you want to buy more poperties use both your cash reserve and line of equity. You can cash out the cash-bought houses to buy more properties in future.
If you have equity in your primary home, get it out and don't let it sleep there doing nothing.
If you can get conventional loans easily, then use your cash reserve and line of equity as down pay to buy multiple properties in a short period of time.
This is an agressive approach and you can use it if you have a good salary income.