How do I finance this commercial office deal?

[Bennet Sebastian]

OK, so I'm going to try and follow the suggested framework for asking financing questions. 

Your goals and story: 

I am in the early stages of evaluating the purchase of a small multi-tenant office building that is 50% partially leased with an asking price of $500k. The remaining space is a shell and would need to be built out at a cost of an additional $100k.

Type of property: 

Office

Location of property:  

Central Florida

Purpose of financing: 

Purchase, renovate and buildout. 

Type of financing sought: 

Not sure. 

Current or prior ownership of real estate: 

I own one medical office currently. Have owned, leased and flipped several offices and a townhouse in the past five years. 

Occupancy: 

Gross lease at $15/sf (about $10 NNN) on half the space. Tenant is on a 1 year lease with several 1 year renewals.

Value of property at present and/or your offer price: 

$450,000

After repair value: 

$780,000 based on a $62,500 NOI and an 8% cap rate.

Anticipated or actual appraisal issues: 

Not sure

Current rents per month: 

$15/sf gross

Fair market rents per month: 

$15/sf gross

Down payment or equity: 

Depends on the loan amount available

Source of down payment funds, if applicable: 

Own funds and limited partners

Income Source: 

Day job is general contracting

FICO: 

Excellent

Credit issues: 

None

Additional details: 

Goal is to hold this property for between three and five years. Purchase price of $500k and improvements of $100 for a total requirement of $600k. Should I use short term private money to purchase and buildout the property and then put conventional financing after it's stabilized? If so what kind of terms would I be looking at? Wondering what would be the appropriate financing strategy here. 

Thanks