So I could take a portion from my 401k and a portion from my business LLC account.

The downside is you will need to live there, for a minimum of one year (to satisfy FHA Requirements); AND because you closed personally, you will not have Asset Protection, in the form of closing in the name of a LLC.

I have 13 years of residential remodeling experience, operate a one man residential construction LLC, and have a mentor with 30 years of residential remodeling experience that includes 4 flips.Here are the Deal Details:$450,000 = Property Value before renovations began$350,000 = Current value of property$220,000 = Current Mortgage held by parents$160,000 = Cost of making sale ready$380,000 = Parents total investment$500,000 = After Repair Value (conservative estimate)$120,000 = Profit of project$(10,000) = Loss of current equityHere's the Scope of Phase 1:Finishing current 1000 sqft renovationNew 1000 sqft garageNew 100 ft drivewayRenovating 1,500 sqft craftsman barnNew septic systemNew water wellAdditional Information:Despite that the property could sell currently for $130,000 net and the estimated profit will only be $120,000, my parents still want to continue with the project. 

It's owned by my LLC, closed in about 2-3 weeks, and based solely on the cashflow it's bringing in (1.1 DSCR).

LLC formation?

Unless you invest via an LLC owned by the IRA, you will not have checkbook control over the funds which means you need to run transactions (e.g. income, expenses, etc.) through the trust company who will need time to process the transactions and generally charge fees for each transaction.

Commercial lending, to my knowledge, requires an LLC.

Does Kirkpatrick Bank typically allow purchases of rental properties on bank loans made to a person instead of an LLC, or are they adding functionality in other arenas, too?

I set up a parent LLC (not a series) for my properties (each have a LLC).

Being my first deal should I get an LLC before I refinance and put the 150k in the LLC and than have the LLC purchase the property or should I purchase the house personally and than give it to the LLC?