The suggestion given to you earlier about joining a local REIA meeting, group, club I would highly recommend because there you will meet other investors who can help you along with contractors and others.

However, I'm not able to find anything that would suggest this is illegal.

Any suggestions on how to negotiate owner financing rather than typical 20% down and 30 year mortgage?

I would suggest looking outside of OC into San Bernardino County or riverside county if you want to get over a 5% cap rate.

Any suggestions?  

or do you suggest a grace period?

Suggestions of companies etc?

I've been studying up for months now it's time to actually get out there and make moves.

@Simcha Davidman seek for a local wholesaler and learn the trade, you will get the best deals that way, I agree with @Judy P. when she suggests to start with Single Family, what if you really don't like being a landlord of one family, how will you handle multiple? 

Study and research most of cities/states now,it seems we are in seller market now?