Sounds like you have a lot offer this group, and hopefully the members here can help you with their advice in return.Just to introduce myself - I'm a real estate broker and have been helping buyers and sellers with their real estate needs for about 20 years.

Foreclosure lists I think can be determined at some sites like propstream (I've never used it so I could be wrong).3: networking with lawyers that do probate situation and/or divorce situations and want a quick close4: Owner occupant of a property on Hud Homestore - basically trying to help first time homebuyers buy - less competition5: tax auction and tax auction sites6: Offering on properties that have been sitting on the MLS for LONG periods of time and low balling them.7: Calling owners that have recently had their property pulled from the MLS.8: Wholesalers that are selling to you with an assignment fee.9: Low balling every property you look at on the MLS and seeing what sticks.10: FSBO with strong negotiation skills.11: MLS when you see the property really quick once it comes on MLS and put in a full price offer but it was mispriced low (I got a gem a few years ago that has probably close to doubled in values since 2020 when I bought it).12: MLS offers that you really want to ownI might be missing some others but these are the general classes of people that I have noticed. 

My question is how or what would a silent partner get from a deal like this, or what can I offer if they would provide 20% of the cost of the building only?

Please let me know if I can answer any questions or offer support in any way.

Some Insurance companies offer coverage for those lines as an endorsement. 

I found a great deal on an older but very well maintained manufactured home in the a very nice area of san Fernando valley. 

Unless the city was offering grants or something to incentivize it, it is a risky proposition. 

When you find a great deal and want to sign a contract with the seller do you sign it before you find a buyer or do talk to buyer, discuss the deals numbers such as and Max acceptable offer, what work needs to be done on the house ... etc. and then sign the contract with the seller once the criteria with the buyer has been met. 

BiggerPockets has so much to offer.

Additionally, Blue Ribbon Homes includes a property management team explicitly designed to handle my portfolio and is now offering a range of services to other investors.