While reviewing them, I learned that both of the duplex units were experiencing foundation issues/sinking floors over the past couple of years.

They are very tricky loans, and they require an experienced lender and general contractor.

I hope other experienced investors can point us to single sources, but suspect the tools and knowledge is gained from many angles (books, podcasts, seminars, mentors, etc.) and experiences (successes and failures). 

Find a broker that has a training program, or is happy to mentor, or where there are experienced agents willing to offer some guidance.

The thing you need to watch out for with a large national firm is that your experience will only be as good as the sales rep assigned to you and many times these are not necessarily experienced senior consultants with longevity in the field.I'd focus more on experience and responsiveness than on location and you'll be fine.

 - I'm sure you will be successful ... my advice was intended to reduce the difficulty of your journey .... to put it bluntly, without employment you will have an uphill battle acquiring property - A job makes that task EASY (maybe your wife has a job) .... sacrifice your "lifestyle" for a few years and then live however you want when you no longer need any income beyond your investment income - for me that was a 4-5 year processOn the multi-family, I say if you like it buy it --- As for the specific numbers on the 4plex....

You'll need to define each of your roles before you can come up with a split that is "fair" This is just a common sense approach though as I'm not an experienced investor myself. 

In this market adding properties is difficult; I am finding MF is way over priced and not enough CF, at least not for me.

@Ashanta KellyWelcome to BP, I'll be happy to help as an experienced Investor and Real Estate Broker!

Also can be a bureaucratic mess to get approval but this can be mitigated by working with a bank who is VERY experienced in doing these loans.