Is 20% down a good plan or should I do less and use the extra money for updates to the house?

Thought about just building because I can get a basic house completed in about 90 days after receiving permit, but haven't been able to find any decent lots.

My build permit checklist has no sign off on from the inspector for the footings and stem walls.

The units come pre-loaded with freon so dont let anyone charge you extra for that.

Oftentimes the seller will base the price on current rents and depending how far below market they are you can get a unit that is renting for $1100 that should be renting for $2000 to live in by paying the extra $15,000-$20,000 in relocation assistance, which if you treat it like an increase in purchase price is a pretty good deal. 

If so, is the extra $400 worth your time?

Got a permit for that one?".    

It's a 3 unit 129k with a new roof, new windows, new flooring, My mortgage will be roughly 1200/month, if I can rent the other two units for 1200/month, then I live for free and have an extra +/-$1200/month to put away every month as well as the income from my full time job, even at 100% vacancy, my mortgage is lower than buying a single family home and also lower than renting. 

Not only do you have to deal with the rehab, you may have to deal with all kinds of government issues from permitting to zoning.  

We are not our tenants bank and they are not permitted to borrow our money for any reason.I believe it is a responsible landlords obligation to train all tenants to be good tenants.