It sounds like you haven't defined a "deal that works" or looked at enough creative options in California yet. 

The delayed financing option bases value on the appraised value not the purchase price, but you can only borrow price plus cost which still results in same concerns you have about that option.

The study identifies with forensic engineering detail the immediate Bonus Depreciation 5, 7 and 15-year personal property class lives qualifying portions of a building that are normally buried in 27.5 year residential or 39 year commercial categories.

We are looking for options to help continue portfolio growth.Thanks 

It’s good to know that these options exist.

One of the duplexes is actually a lease option with a 30 year note.

Instead of converting into a multi family I was exploring other options. 

Quote from @Rowan Miele: When it comes to loans, check out FHA or conventional options, and maybe chat with a local lender for specifics. 

There are several different options whether it be passively investing utilizing some of the larger companies who do all the work for you or more active investment that will make your money go a little farther if you are comfortable doing more work.

Yes - LLCs can get 30-year loans - as others have mentioned, DSCR Loans are probably your best option.