Out of principle, we don't use credit cards.

My objective is to become known and, most importantly, trusted by these people.

Do you make a distinction between mobile and manufactured, or are they more or less governed by the same principles?

The HELOC pmt would be approx $800/mo so you'd net $400/mo cash flow + principle pay down. 

To be clear, the pay off is the principle balance plus any accrued interest and fees, etc. if the loan is behind. 

Is your objection petty or something serious?  

I am currently using a spreadsheet, which is ok for regular payments but it gets problematic with late payments, NSF, extra principle, etc.Has anyone found software that is beneficial to DYI lenders?

I think if finding a no money down deal is your starting objective its going to be a very difficult proposition. 

Our first objective is to make enough income from rent to cover our expenses, and then move into a single-family home.

Trust me on this: you will always be able to tell professional workmanship.This same principle applies to most labor, whether it’s replacing a foundation or painting a wall.