You can do it as a joint venture where you partner will also likely sign and guarantee on the debt, or you can have an investor provide you debt.  

It might specify that you need to get the seller's approval before you change lenders or loan packages. 

My partner and I got an FHA loan approval about a month ago so we've been working with a local real estate agent to view properties.

In NJ there was also requirement to get approval from the state.

My husband and i are still looking at different properties but we are unsure if we should get pre-approved for a loan first before making any decision since we are not sure what the approval amount will be.

Also if you have to VA loans together, so you and a friends that has VA entitlement then you can get approved for a 6 unit with one commercial space. 

As a realtor if investor or buyer not approved after 1st time showing, I ask him I can wait until the letter is ready and give him leads.

The Taxable Value is uncapped and equated to the SEV upon a sale or other transfer of property ownership, with limited exceptions.Once you know the Taxable Value, you can look up the property tax millage rates, which each city & county sets separately (with voter approval).So, yes, it is very possible for property taxes to jump from $907 to $3200 if the seller has owned the property for quite some time.You can use this tool to estimate your future taxes after they are uncapped: https://www.michigan.gov/taxes/0,4676,7-238-43535_43540---,00.html

You put your tenant in charge and from what you have told us made zero communication regarding price, limits, approvals etc.  

I think your first step should be getting in contact with your current lender and seeing what you would qualify for in terms of financing at this point, then delve into the realm of new construction loans pre approval once you have a ballpark of how much a new build will cost.