You may want to get in touch with some realtors in whichever markets you are interested in that specialize in off market deals (pocket listings) and who are also "investor friendly realtors," not just ones that want to off a garbage property to you.

which ever comes first ? 

On the house hack, you can divide common expenses by square footage or bedrooms, whichever is more advantageous. 

Proc. 2004-51, 2004-2 C.B. 294, that fall on or after the date of a federally declared disaster, are postponed by 120 days or to the last day of the general disaster extension period authorized by an IRS News Release or other guidance announcing tax relief for victims of the specific federally declared disaster, whichever is later.

Whichever path you choose (likely one between those two) will be hard.

Quote from @Zachary Engen: Ive read a few things about onlying being able to cash out refinance 75% or the purchase +closing costs, whichever is lower.

California law in regards to deposits on residential projects is 10% of the total proposed project value or $1,000.00, whichever is less.

The basics of a seller financed deal are that the title co or closing attorney (if there is one) or seller’s attorney draws up the warranty deed transfers title, the promissory note evidencing the debt related to the transaction, and either the deed of trust or mortgage (whichever is being used) perfecting the lien against the subject property.  

Clarity shows commitment and improves your chances of obtaining funding, whichever property you choose.

I think their general stance is going to be to go with whichever comparable property has the greatest degree of similarity in terms of (probably, in this order): location, age built, quality of construction/current condition, and square footage.