If anyone else replies they've had success, has anyone been able to "sell" this concept to a bank that otherwise had policies in place that didn't accommodate this type of lending?

Citimortgage is pretty accommodating to multiple-mortgage borrowers.

Make it adjustable starting low, so you can accommodate the buyer somewhat.

I've seen inspectors be pretty accommodating when an oversight was clearly on them.

I'd say in this case it is time to find someone local to you that is able to accommodate that. 

And just add to the conversation, the reason I feel that starting in a SFH is a wise move is because I have a family of 6 including myself so finding a MFR that accommodates us is proving to be difficult, I figure that I can have a house for my family and rent it out when the time comes while learning how to do minor jobs myself without a huge rush, IF SOLD I would aim for avoiding the capital gains tax after at least 2 years.

All that said, just make sure you ask the engineer how his design accommodates the flood plain and understand what construction costs might come from it.

Meanwhile, am seeking to lease an accommodation for my wife's school with no or low money down.

Tenants often don't keep the property is show ready condition and aren't accommodating to showing the home.

One I explain that anything less than a 5 star rating or 10/10 (We use booking and expedia as well) actually hurts our business so please let us know if you as the guest are not having a 5 star say, so we can do our best to accommodate.