If you have ~25 units at $500/month rent increase you $12.5K/month of increase or $150K/year in the increase.I recognize that there are Californians that cannot afford to purchase a turnkey non owner occuppied property via traditional financing in CA. 

I’m looking forward to making connections for creative financing, advice on rentals, and just overall rapport with others on the same track. 

Are you going to buy solid properties in good neighborhoods with conventional financing, and then 'cash flow' in month 1 or year 1, or even in the first few years? 

Seller financing still implies a transaction and therefore a tax event.

Can't do another HELOC...Is seller financing the only option in this case?

Begin researching regulations, financing options, and potential GCs well in advance.

I then rehab the property and finance it or sell it.

The property is a 7% caprate, this the best deal I've seen personally in the last 9 months, it was an off market seller who is doing seller financing.

I am negotiating the purchase of an investment property in Hawaii. It has two separate dwellings on one lot. One house is a 3br/2,5ba, with full kitchen, and the second house has a 2br/2ba with full kitchen on the top...

Buy a 2-4 unit with an FHA 203(k) loan which allows you to finance repairs into the purchase mortgage.