My wife will materially participate in the business and I'll provide the financial backing.I've talked to a couple local CPAs and done a fair bit of internet searching on legal entity setup for my situation, but haven't been able to get a straight answer.

First thing you need to do is separate the two entities- the house and the park.The house- Get the appraised value of the home which should be easy enough to do. 

The mortgagor has topmost redemption rights, then the borrower,  if those are two different people/entities.

You will need to make some modifications, such as property management and branding entities.

And your IRA/401k is a separate legal entity from you.

First, ensuring that each property or group of properties is held in a separate LLC can limit exposure, confining potential liability to the specific entity involved.

An LLC is a disregarded entity for tax purposes.

The presumption is that legal entities are excellent tools, as long as you follow the corporate maintenance and corporate formalities. 

If your entities are disregarded, you may be able to have them within the same QBO and keep up with each using the location/business feature.

We've found it has superior reporting features, integration features, and is overall more efficient to work within than other REI-specific software.The downside is QBO is not set up for REI so you'll need to do that or work with an expert to ensure it is set up for your business appropriately.Something else to keep in mind is your entity structure and how your entities file tax returns.