If you qualify traditional financing is almost always cheaper. 

We have a pretty large lot, .71 acre and are thinking about building a tiny/small house on the back side of our lot and renting our current house(3 bed 2 bath) either through airbnb or traditional tenants.

I've tried the traditional loan, but my credit is not what it needs to be.  

If I'm using traditional model for 1-3 units and outsourcing management at 10%, after collecting rent (let's say $1,000 per month per unit), mortgage, taxes, insurance, vacancy, maintenance and management, I should be able to cash flow around $300 depending on taxes at 100% occupancy.

I plan to use a traditional 30yr fixed owner occupant loan.  

Which one is better: FHA or a traditional loan?

We are considering modular or traditional builds.The problem:My partners and I manage a portfolio of property that spans multiple states and a variety of property types.

Since this is the first time I've re-fi'd any rental property is this better then a traditional bank who gives up to 75% of property value?

Are there the same requirements as if I’m getting s traditional mortgage?

He previously applied for a traditional home loan and was denied because it does not meet the secondary market requirements.