Good news, we have been approved to convert the SFH into a duplex!

The neighbor seems to think that the previous owner just added it without getting any sort of permits or approval from the city.

In my area, local banks are hungry for small apartment deals and they'll be happy to work with you if you have a decent deal.I'm a bit late to this but if you take a pro forma of the 6 unit to a lender I'm sure they'd give you a pre-approval letter.I've also never been asked for that though unless the seller was a large bank/ government agency.

Non-licensed folks aren't required to use the state approved Offer to Purchase. 

I "house hacked" like @Dorothy Ma mentions above, however VA loans have a cap around $420k, and you're very unlikely to find a multifamily property in Denver that will be approved for the loan at that price point.

*Possibly Georgia, Texas or Florida* Small multifamily and mobile homes

Very nice feature for young "upwardly mobile" types. 

After reading books and listening to Brandon and Josh on the podcast, we are convinced that we need to start with a multifamily (preferably a 4-plex).We have been pre-approved for an FHA, and have looked into a 203k Loan.

Just received HOA approval to rent out the condo we are currently living in.

You seem to know a bit about Mobile homes.