The owner has paid so far $70,000 on his mortgage(bought the property for $105,000) but due to personal reason he hasn't been able to make last few months mortgages, in total he is $5,000 behind.

I think all you need is a title company to close your transactions - no don't need an account at this time - most title companies have lawyers to close your transactions -You should make sure that you buy real estate at a giant discount - Understand the management process - learn how to be a good landlord - a tenant is a customer - the tenant is the person who will pay for your mortgage - treat them well.Find discounted real estate from landlords who find themselves in rent court -Start to deal directly with owners - I don't think you should depend on agents selling retail properties - you need to go under-ground for great deals -Tax salesPublic AuctionsRun print ads and radio commercialsInternet - 5 weeks ago I created an internet site - I have received over 200 leads - have 70 offers out there and 15 ratified contracts - learn those systems and you will do well.Expired listings - go knock on some of those doors - an expired listing is  FAILURE of property to sell - I am sure the sellers are not happy - go find them and solve their problems.Direct mail to commercial properties owners - commercial buildings can be  great profit center - when you advertise for real estate - signs - internet or mailings always advertise - WANTED REAL ESTATE - houses - commercial and non-conforming properties - all cash -as is - no commission.

Couple A is willing to live in the bottom portion in order to get the better rate and less down since it will be owner occupied.

The current owner had a partnership in it, which dissolved and is why they are selling.

Following are the similarities and differences between the solo 401k and the self-directed IRA.The Self-Directed IRA and Solo 401k Similarities Both were created by congress for individuals to save for retirement;Both may be invested in alternative investments such as real estate, precious metals tax liens, promissory notes, private company shares, and stocks and mutual funds, to name a few;Both allow for Roth contributions;Both are subject to prohibited transaction rules;Both are subject to federal taxes at time of distribution;Both allow for checkbook control for placing alternative investments;Both may be invested in annuities;Both are protected from creditors;Both allow for nondeductible contributions; andBoth are prohibited from investing in assets listed under I.R.C. 408(m).The Self-Directed IRA and Solo 401k DifferencesIn order to open a solo 401k, self-employment, whether on a part-time or full-time basis, is required;To open a self-directed IRA, self-employment income is not required;In order to gain IRA checkbook control over the self-directed IRA funds, a limited liability company (IRA LLC) must be utilized;The solo 401k allows for checkbook control from the onset;The solo 401k allows for personal loan known as a solo 401k loan;It is prohibited to borrow from your IRA;The Solo 401k may be invested in life insurance;The self-directed IRA may not be invested in life insurance;The solo 401k allow for high contribution amounts (for 2016; the solo 401k contribution limit is $53,000, whereas the self-directed IRA contribution limit is $5,500);The solo 401k business owner can serve as trustee of the solo 401k;The self-directed IRA participant/owner may not serve as trustee or custodian of her IRA; instead, a trust company or bank institution is required;When distributions commence from the solo 401k a mandatory 20% of federal taxes must be withheld from each distribution and submitted electronically to the IRS by the 15th of the month following the date of each distribution;Rollovers and/or transfers from IRAs or qualified plans (e.g., former employer 401k) to a solo 401k are not reported on Form 5498, but rather on Form 5500-EZ, but only if the air market value of the solo 401k exceeds $250K as of the end of the plan year (generally 12/31);When funds are rolled over or transferred from an IRA or 401k to a self-directed IRA, the amount deposited into the self-directed IRA is reported on Form 5498 by the receiving self-directed IRA custodian by May of the year following the rollover/transfer.Rollovers (provided the 60 day rollover window is satisfied) from an IRA to a Solo 401k or self-directed IRA are reported on lines 15a and 15b of Form 1040;Pre-tax IRA contributions on reported on line 32 of Form 1040;Pre-tax solo 401k contributions are reported on line 28 of Form 1040;Roth solo 401k funds are subject to RMDs;A Roth 401k may be transferred to a Roth IRA (Note that from a planning perspective, it may be advantageous to transfer Roth Solo 401k funds to a Roth IRA before turning age 70 ½ in order to escape the Roth RMD requirement applicable to Roth 401k contributions including Roth Solo 401k contributions and earnings.)

Side note, if the home is on a septic system it is usually on the owner to pump this.

what is typical for a down payment if someone owner finances?

The previous owner had carpet on it, but they removed it and I've been left with plywood only.

I want to see if this is possible and how to approach the owner if so.

I have been talking with an owner about maybe owner financing his duplex here in Florida.