I would like to sue and also report the owner (licensed broker) to the state (Wisconsin).

imho the 121 and 1031 are two of the best features of the tax law benefitting real estate owners. 

The problem as mentioned above is that anything owner-occupied is going to come with a huge amount of regulations and legal compliance - its why most private lenders will not do loans like this even though they would do it in the same exact situation if the unit was a rental

I'm guessing the owner won't provide financing for you?

@Wai-Lin William Maw You may want to talk to some experienced park managers and owners in the area who have done the same thing.

I need lists of owners of vacant parcels of residential land.

He categorizes transactions, reconciles accounts, manages payroll, collections, builds & sends owner statements to clients, and generates our p&l at the end of the month.

Look at lists of properties that are on the Sheriff Sale, and Tax Sales, as some of those could have assumable mortgages, and provide a list of potential assumable mortgages, where the owners are potentially losing their properties.David KrulacBigger Pockets Podcast guest #82  

I'm unsure what the right path is, but I've been reading & watching podcasts about investing in owner-occupied, single family properties.

For example, an owner headed to foreclosure might sell you a property "Subject-To" where you take over their loan at a LOW LOW rate which changes the math a LOT when analyzing a deal!