Broker wants a pre-appvoval letter prior to showing finances

[Toben B.]

I am dealing with a broker that wants a pre-approval letter prior to showing me finances on a mobile home park. 

He is a residential real estate agent and this is a ridiculous request. However does anyone know a lender or a bank that will generate a pre-approval letter? My bank will on apartments but not mobile home parks. 

Obviously this letter will have a be non-binding and depending on the park financials. 

Thanks