They might also consider a participation partnership with me but are asking for my mortgage loan payoff balance amount to acturately put together a proposal.

Since you are active participants in your employer plan, there is a limitation on deductibility for tax (you can always contribute to IRA, but tax deductibility is dependent on your AGI if you are an active participant).

@Jared Ottley Try an more institutional bank too.

Cost segregation likely won't help for 2018 tax return.Do you have atleast active participation in your properties?

What is funny is that you discredit that style of investing but then participate in it through your 401K, pension and social security...

Next, if there isn't, I'd go to the institutional lending trade assn. and from there, find out who knows hard money. 

Few investors and lenders would want to participate in an unsecured loan.  

@Nicholas MorganThe process is identical like regular taxable account:mortgage/note on the property for the funds; property insurance to have the lender as lien holdertitle insurance for the lenderThe SDIRA account institutions; have forms to fill and the lender has to do that. 

From my understanding, question about when to syndicate vs JV is not based on size of the project but rather participation of parties involved. 

Can anyone recommend a local bank or financial institution that would be willing to work with us?